ACUS01 KWNS 091206
SWODY1
SPC AC 091205

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0705 AM CDT Sun Jul 09 2023

Valid 091300Z - 101200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE ARKLATEX
REGION INTO THE GULF COAST STATES...AND OVER THE MID-ATLANTIC
REGION....

...SUMMARY...
Strong storms may pose a risk for damaging wind gusts from the
southern Great Plains Red River Valley through the lower Mississippi
Valley today, with a risk for damaging wind gusts also accompanying
scattered strong storms across the Mid Atlantic.

...Arklatex into Gulf Coast states...
A fast-moving bowing MCS is tracking across southeast OK this
morning. This system has a history of damaging wind gusts and hail
across much of western/southern OK overnight. Radar trends suggest
that activity is slowly weakening. However, at least isolated
gusty/damaging winds are possible this morning as storms track into
northeast TX, southern AR, and northern LA. See MCD #1471 for
further short-term details.

By early afternoon, thunderstorms are expected to intensify along a
cold front sagging across AR/TN. This activity will spread
southeastward across much of northern MS/AL and northwest GA through
the evening hours with a risk of locally damaging wind gusts and
hail.

Finally, multiple clusters of storms are may form this afternoon
ahead of the remnant aforementioned MCS over parts of southern MS/AL
into the FL panhandle. This will be in a region of hot/humid
boundary-layer air and beneath 25-35 knot westerly mid-level winds.
The strongest storms will pose a risk of locally damaging wind
gusts.

...Mid Atlantic Region...
Morning water vapor/radar images show an area of showers and
thunderstorms over WV. This is in association with a mid-level
shortwave trough that will progress eastward across the Mid-Atlantic
states and Carolinas today. While considerable cloud cover is
expected to persist across the region, sufficient destabilization
should occur to aid in thunderstorm intensification as storms move
off the Blue Ridge by early afternoon. Activity will spread
eastward into parts of eastern PA, eastern VA/MD, and NJ/DE through
the late afternoon and early evening. Forecast soundings show
sufficient CAPE and westerly flow aloft to pose some risk of locally
damaging wind gusts in the stronger cells through much of the
afternoon.

..Hart/Leitman.. 07/09/2023

$$
--- SBBSecho 3.14-Linux
* Origin: Ilink: CCO - capitolcityonline.net (454:1/105)

ACUS01 KWNS 112002
SWODY1
SPC AC 112000

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0300 PM CDT Tue Jul 11 2023

Valid 112000Z - 121200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE NORTHERN/CENTRAL PLAINS INTO THE MIDWEST...

...SUMMARY...
Supercells capable of large to very large hail are possible this
afternoon and evening from eastern Montana and western South Dakota
into Nebraska. One or more convective lines may evolve late this
evening and overnight from central Nebraska into Iowa. Severe wind
gusts may occur with this convection.

...20Z Update...
The Slight Risk area has been expanded to include more of
northeastern MT, western ND, and northwestern SD. Multiple
supercells capable of producing large to very large hail should
spread east-southeastward across this area through the rest of the
afternoon and evening. See Mesoscale Discussion 1498 for more
details on the short-term severe threat across this region.

Otherwise, minimal changes have been made to the ongoing forecast.
Additional convection should eventually develop across parts of NE
along/near a front as low-level warm advection gradually increases
later this evening. This activity may initially pose a threat for
large hail. But, quick upscale growth into an MCS should occur, with
a greater threat for severe/damaging winds through the overnight
hours across eastern NE into IA.

Reference Mesoscale Discussion 1499 for additional information
regarding thunderstorms which have recently developed across parts
of northern IL and far northwestern IN along a weak front. Isolated
strong to severe wind gusts should be the main threat with this
activity.

..Gleason.. 07/11/2023

.PREV DISCUSSION... /ISSUED 1130 AM CDT Tue Jul 11 2023/

...Eastern MT into SD/NE...
Early morning surface analysis places a lee trough across eastern MT
to weak low over the northwest NE. Airmass in the vicinity of the
lee trough is currently characterized by mid 50s to low 60s
dewpoints. Modest mid-level warm advection is fostering widespread
cloud cover to the east of the lee troughing across far eastern MT
and the Dakotas. This area of cloud cover is forecast to shift
eastward over time, allowing for daytime heating to destabilize the
air mass. Low-level convergence along the lee trough will be
augmented by increasing large-scale forcing as the shortwave trough
currently over western MT moves eastward into the region.

This combination of air mass destabilization and forcing for ascent
is expected to foster thunderstorm development across western MT
during the afternoon. Low 60s afternoon dewpoints and temperatures
in the 80s beneath steep mid-level lapse rates will support moderate
to strong buoyancy, with MLCAPE from 1500 to 2500 J/kg. Enhanced
mid-level flow will extend across the region as well, supporting
long hodographs and 50+ kt of 0-6 km vertical shear. These
environmental conditions will result in an initially supercellular
mode, with large to very large hail possible for both left and right
splits. High cloud bases suggest strong downbursts are possible as
well. Evolution into one or more bowing segments is anticipated
after a few hours, with these segments progressing eastward into
southwest ND and western SD during the evening, and eventually into
parts of NE. Severe threat will continue with these bowing segments,
with damaging gusts as the primary risk.

...Central SD/NE into IA...
Early morning surface analysis places a cold front from southern IA
westward across central NE, linking up with lee troughing across
eastern MT via a weak low over the northwest NE Panhandle. Elevated
showers and thunderstorm are currently ongoing north of the front
across central SD and central NE, with outflow from these storms now
emerging across north-central NE. A trend towards more surface-based
activity is possible as this outflow continues
southward/southeastward as well as with the more southerly storm
across central NE. There is also the chance for more in-situ
development along the front later this afternoon if skies clear.
Main uncertainty is whether or not the air mass sufficiently
destabilizes given the current cloudiness and relatively warm
mid-levels. As such, a conditional threat for severe thunderstorm is anticipated throughout the afternoon and into the evening, with
strong shear likely supporting supercells capable of large to very
large hail and damaging gusts.

Later this evening, whatever evolves out of the upstream activity
across eastern MT and NE Panhandle will likely progress into the
region, supporting the potential for damaging gusts and isolated
hail throughout the night. Some significant gusts are possible,
depending on how organized the system is as it moves into central
NE. Even at this shorter range, guidance remains varied on the
preferred corridor for this potential MCS, limiting the confidence
needed to introduce higher wind probabilities with this outlook.

...North TX into southern MS/AL...
MCS that moved across OK last night has weakened considerably, but a well-developed MCV in it wake. This MCV is forecast to drift
southeastward throughout the day, with thunderstorms likely in its
vicinity as well as along the leading edge of the
southeastward-progressing outflow. Winds aloft are weak, which
should keep the overall severity limited, with a risk of locally
damaging wind gusts in the stronger cells.

$$
--- SBBSecho 3.14-Linux
* Origin: Ilink: CCO - capitolcityonline.net (454:1/105)

ACUS01 KWNS 120553
SWODY1
SPC AC 120551

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1251 AM CDT Wed Jul 12 2023

Valid 121200Z - 131200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE
CENTRAL PLAINS INTO THE MIDWEST...

...SUMMARY...
Severe thunderstorms will be possible across much of Missouri,
Illinois, and adjacent portions of the central Plains and Midwest on
Wednesday. Damaging winds and large hail should be the main threats,
with some potential for significant (75+ mph) severe winds across
parts of Missouri and vicinity.

...Synopsis...
A strong shortwave trough will continue across the northern Plains
through this morning. Strong mid-level winds will be present across
parts of the central Plains into the Midwest. At the surface, a
boundary will be situated from Nebraska/Iowa becoming more diffuse
farther eastward into New England.

...Kansas/Missouri...
Convection is expected to be ongoing this morning in parts of
Nebraska and Iowa. Outflow from this convection will delimit the
northern edge of greater severe risk during the afternoon. To the
southwest, a frontal-wave cyclone will move east along the northern
baroclinic zone and push a cold front into central/western Kansas.
The convective outflow and cold front will serve as foci for
additional development during the afternoon. Strong heating of a
moist (upper 60s/low 70s dewpoints) airmass will promote strong
buoyancy (3000-3500 J/kg MLCAPE). Mid-level lapse rates and
low-level moisture will be less favorable with eastward extent to
some degree. Shear across the region will be relatively strong given
the strength of mid/upper-level winds for this time of year. Initial
storms will likely be supercellular and be capable of large to very
large hail. As upscale growth occurs, intense winds will be
possible, some in excess of 75 mph. A more organized wind threat may
occur wherever the buoyancy gradient is located. Enough uncertainty
still exists that an increase in unconditional severe wind
probabilities is not warranted.

...Midwest...
Greater forecast complexity exists for parts of Iowa into Illinois.
Convection will likely be ongoing in Iowa early this morning. The
overall strength of that activity is somewhat uncertain given a
likely more stabilized boundary layer by that time. Remnants of this
activity are expected to generally move eastward. Some
reintensification is possible from northeast Missouri into central
Illinois. However, more modest lapse rates aloft and slightly lower
low-level moisture (particularly farther east) should limit the
spatial extent of the severe risk with time. Strong/damaging winds
will be the primary risk, though isolated large hail is also
possible.

...Lower Great Lakes into New England...
Storms will be possible along the weak surface boundary during the
afternoon. Broad cyclonic flow aloft will provide sufficient shear
for marginally organized convection. Damaging winds will be the main
hazard from locally strong downbursts.

..Wendt/Thornton.. 07/12/2023

$$
--- SBBSecho 3.14-Linux
* Origin: Ilink: CCO - capitolcityonline.net (454:1/105)

ACUS01 KWNS 151211
SWODY1
SPC AC 151209

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0709 AM CDT Sat Jul 15 2023

Valid 151300Z - 161200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND
EVENING OVER PARTS OF NORTHEAST NEW MEXICO AND THE TEXAS
PANHANDLE....

...SUMMARY...
Scattered severe thunderstorms are expected across the High Plains
of eastern New Mexico into the Texas South Plains. Hail and wind are
the main threats with this activity. Isolated strong storms may also
be noted across portions of the Appalachian region.

...Eastern NM/West TX...
Scattered showers and thunderstorms have been occurring overnight
across much of the TX Panhandle. This activity will dissipate later
this morning, but leave a surface outflow boundary that stretches
from south of LBB into eastern NM. The air mass to the north of
this boundary should recover later today, as dewpoints in the 60s
and south-southeasterly low-level winds provide a moist upslope flow
into the Raton ridge area of northeast NM. Large scale forcing is
subtle, but thunderstorm development is expected over the mountains
on northeast NM and spread southeastward toward the TX Panhandle by
evening. 25-30 knot northwest flow aloft, coupled with moderate
CAPE values and very steep mid-level lapse rates, will be favorable
for a few supercells capable of large hail. However, storms are
likely to congeal into bowing structures with an increased risk of
damaging winds

...Ohio Valley/Appalachians...
A broad upper trough is present today over much of the eastern
states. Scattered thunderstorms are ongoing this morning from lower
MI into IN/KY/TN ahead of a weak cold front. Mid-level lapse rates
are not particularly steep and widespread clouds will limit daytime heating/destabilization. This suggests that despite considerable
coverage of thunderstorms today over the region, most of the
activity will remain below severe limits. Nevertheless, pockets of
greater heating or mesoscale organization of convective clusters
could result in locally strong/damaging wind gusts.

..Hart/Kerr.. 07/15/2023

$$
--- SBBSecho 3.14-Linux
* Origin: Ilink: CCO - capitolcityonline.net (454:1/105)

ACUS01 KWNS 161257
SWODY1
SPC AC 161255

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0755 AM CDT Sun Jul 16 2023

Valid 161300Z - 171200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF
THE NORTHEAST/NEW ENGLAND AND CENTRAL PLAINS...

...SUMMARY...
A few tornadoes will be possible across portions of the Northeast.
Scattered large hail and severe wind is possible across the Central
Plains.

...Northeast/Southern New England and Mid-Atlantic States...
An extremely moist airmass exists across the region 1.9-2.2 inch
Precipitable Water values and middle 70s F surface dewpoints from
the Carolinas to New England. Multiple relatively subtle
low-amplitude disturbances appear to be generally moving
east-northeastward over the region this morning amidst
trough-preceding moderately strong deep-layer southwesterly flow.

Considerable cloud cover and scattered early day convection will
tend to temper overall buoyancy, but even so, diurnal heating and
even minimal cloud breaks should enhanced updraft intensities
through the morning into afternoon, with a corresponding increase in
severe risk. The strongest low/mid-tropospheric winds (1-3km AGL in
particular) will be focused from the southern New York/northern New
Jersey areas into southern New England. This is where the potential
for a few tornadoes should be maximized today, particularly this
morning through early/mid-afternoon, coincident with 100-200 m2/s2
0-1 km SRH. The potential for locally damaging winds will otherwise
exist across a broad part of the region.

...Central Plains/Midwest...
Multiple clusters of storms are ongoing early today across southeast
Nebraska and northeast Kansas. A general persistence of the storms
may occur today across Missouri with an increasing severe risk into
the afternoon as the boundary layer destabilizes.

Across central Kansas, confidence is higher for a very unstable
airmass to develop ahead of potential storm development late this
afternoon into evening. Strong instability and 45-50 kt of effective
shear will support supercell storm mode with the potential for some
very large (2+ inch) hail. Storms may eventually congeal into a
cluster across central Kansas with an increasing damaging wind
threat into the evening.

...North Texas/Southern Oklahoma to ArkLaTex/Middle Gulf Coast...
A slow-moving/loosely organized cluster of storms along and south of
the Red River may persist east/southeastward today, with other peripheral/preceding development possible. This will be within a
very unstable air mass with temperatures in the 90s and dewpoints in
the upper 70s, yielding 3000-4000 J/kg MLCAPE. Damaging wind gusts
will be possible given the degree of instability across the region.

..Guyer/Kerr.. 07/16/2023

$$
--- SBBSecho 3.14-Linux
* Origin: Ilink: CCO - capitolcityonline.net (454:1/105)

ACUS01 KWNS 171655
SWODY1
SPC AC 171653

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1153 AM CDT Mon Jul 17 2023

Valid 171630Z - 181200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE
CENTRAL/SOUTHERN PLAINS EAST TO THE OHIO VALLEY...AND FROM EASTERN
WYOMING INTO SOUTHWEST SOUTH DAKOTA AND NORTHERN NEBRASKA...

...SUMMARY...
Severe storms producing large hail and damaging wind gusts are
mainly expected from the Black Hills southeastward into Nebraska
tonight, and across portions of the Ozarks and Lower Ohio Valley
today.

...Central/southern Plains east Ozarks and Ohio Valley...
Moderately strong northwest/west mid-level flow will persist from
the central/southern Plains east to the OH Valley through tonight.
Heating of a moist air mass ahead of a nearly stationary front,
combined with a plume of steep mid-level lapse rates will result in
a rather large region of strong to locally extreme instability in
the presence of substantial deep-layer shear supportive of organized
storms.

Ongoing severe storm cluster over southeast KS will likely continue
moving south-southeast into an environment characterized by 40-50
kts of shear and MLCAPE of 3000-4000 J/jg. Damaging winds and
potentially very large hail will be possible with this complex as it
moves across northeast OK. Additional thunderstorm development is
likely across the Ozarks vicinity along remnant outflow boundaries
this afternoon, ultimately resulting in additional clusters or line
segments moving southeast/south through this evening. Damaging
winds will be the primary severe threat, and with large (isolated
very large) hail with the more discrete/intense updrafts.

Across the OH Valley, clusters of thunderstorms are expected to
develop as clearing/heating occurs in the wake of morning storms.
Effective shear of 30-40 kts will support both supercell and
multicell clusters persisting through the late afternoon and early
evening with severe wind/hail potential.

...Eastern Wyoming/Black Hills/Nebraska...
A sharpening lee trough ahead of the northern Rockies upper trough
will result in moist low-level upslope flow into the Black
Hills/eastern Wyoming and southeast Montana vicinity. The
proximity of the upper ridge may somewhat temper the extent of
deeper convection, however at least isolated thunderstorms are
expected to develop by late afternoon/early evening in a moderately
unstable and strongly sheared environment, with storms increasing in
coverage toward/after sunset. Steep lapse rates and long straight
hodographs will support large to locally very large (greater than 2
inch diameter) hail. As the low-level jet strengthens during the
evening, upscale development into a bowing MCS is possible as
convection tracks southeastward across western/southern South Dakota
and Nebraska. Damaging gusts, potentially significant, may accompany
this MCS during the evening and overnight hours, and a Significant
Wind area has been added with this outlook.

...Northern Great Basin and Central/Eastern Montana...
Moderate to strong west-southwest mid/upper-level flow will
overspread the region ahead of the northern Rockies upper trough.
Steep mid-level lapse rates and moistening will support MLCAPE
around 500-1250 J/kg. Well-mixed boundary layers will result in
mostly high-based, low-precipitation convection capable of sporadic
strong dry microburst winds from far northeast Nevada/northern Utah
into central Montana. With eastward extent into parts of eastern
Montana, deeper boundary-layer moisture will result in the potential
for isolated strong gusts as well as hail.

...Southern AZ...
Diurnal heating of a moist environment (PW 1.5 inches) will
contribute to afternoon MLCAPE of 1000-1500 J/kg. Thunderstorm
development is expected this afternoon, and dry mid-levels with
15-20 kts of easterly flow will result in a risk for gusty/damaging
winds as storms move west through evening.

..Bunting/Weinman.. 07/17/2023

$$
--- SBBSecho 3.14-Linux
* Origin: Ilink: CCO - capitolcityonline.net (454:1/105)

ACUS01 KWNS 192000
SWODY1
SPC AC 191958

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0258 PM CDT Wed Jul 19 2023

Valid 192000Z - 201200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE CENTRAL PLAINS INTO THE UPPER MIDWEST...AND EASTERN NORTH
CAROLINA INTO SOUTHEASTERN VIRGINIA...

...SUMMARY...
Scattered severe thunderstorms capable of producing damaging winds
and hail are expected this afternoon into tonight across parts of
the Upper Midwest, central Plains, and Mid Atlantic regions. More
isolated strong to severe thunderstorms may also occur from the
Ozarks into the lower Ohio and Tennessee Valleys, and parts of the
Great Basin.

...20Z Update...
The Slight Risk has been expanded across parts of eastern NC based
on recent convective trends. See Mesoscale Discussion 1628 for more
details on the near-term severe threat for this area.

Have trimmed the Marginal Risk across parts of the TN and lower OH
Valley. There still appears to be some potential for strong to
locally severe thunderstorms late tonight into early Thursday
morning over portions of this region as convection spreads eastward
in a modest low-level warm advection regime ahead of an approaching
upper trough.

Small adjustments have also been made to the Marginal/Slight Risk
areas across the mid MO Valley into eastern SD/western MN based on observational and short-term model trends.

..Gleason.. 07/19/2023

.PREV DISCUSSION... /ISSUED 1121 AM CDT Wed Jul 19 2023/

...MN/WI...
An upper low is tracking southeastward out of southern Manitoba into
ND. At the surface, a quasi-stationary boundary extends from
northwest MN southward to near MSP. Westerly low-level winds and
strong heating west of the boundary, combined with backed flow to
the east and more persistent low-level moisture, will lead to an
axis of thunderstorm development this afternoon. Forecast soundings
show low-level and deep-layer shear profiles favorable for rotating
storms capable of hail and gusty winds. A tornado or two is also
possible. These storms will drift eastward into the MN Arrowhead
region and northern WI during the evening.

...Central Plains...
A broad upper ridge is positioned from the Four Corners region
eastward across the southeast states today, with the southern fringe
of stronger westerlies extending across CO/KS. Rich low-level
moisture is present across much of the central Plains, with
dewpoints in the upper 60s and 70s from eastern CO into central NE. Thunderstorms are expected to develop along the western edge of the
greater moisture by mid-afternoon along an axis from north-central
NE into northwest KS and eastern CO. These storms will spread
southeastward through the evening, posing a risk of very large hail
and damaging winds. Activity is expected to build as far south as
parts of the TX/OK Panhandles during the evening.

...KS/MO...
Multiple 12z CAM solutions suggest that a cluster of storms over
northern KS will grow upscale and become very organized late
tonight, resulting in a corridor of severe wind potential from
eastern KS across central into southeast MO. At this point, the
confidence in this scenario remains low but will be monitored.

...VA/NC...
A remnant MCV is evident in satellite/radar imagery over
north-central NC. The associated cluster of thunderstorms will
track northeastward toward the coast this afternoon, posing a risk
of damaging wind gusts. Please refer to MCD #1627 for further
details.

...UT...
A cluster of showers and thunderstorms over western NV is associated
with a weak mid-level shortwave trough. Weak but sufficient forcing
ahead of this system will lead to scattered thunderstorm development
later today over eastern NV and western UT. Forecast soundings show
inverted-v profiles, but with pockets of CAPE around 500-1000 J/kg
and with 25-30 knots of westerly mid-level flow. This will be
sufficient to pose a risk of locally severe wind gusts in the
stronger cells.

$$
--- SBBSecho 3.14-Linux
* Origin: Ilink: CCO - capitolcityonline.net (454:1/105)

ACUS01 KWNS 211932
SWODY1
SPC AC 211930

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0230 PM CDT Fri Jul 21 2023

Valid 212000Z - 221200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE SOUTHEAST...FAR EASTERN NEW YORK INTO SOUTHERN NEW ENGLAND...AND
THE SOUTHERN HIGH PLAINS...

...SUMMARY...
Severe thunderstorms capable of wind damage and some hail are
expected across parts of the the Mid-South and Tennessee Valley to
the Southeast States. Additional severe storms remain possible
across portions of the Northeast and southern/central High Plains.

...20Z Update...
Main change with this update was to expand severe probabilities
northward across parts of the TN Valley based on the track of a
small but intense MCS moving generally eastward across western TN
and far northern MS. Severe/damaging winds will remain the primary
threat with this convection across middle/eastern TN into northern
AL/GA through the rest of the afternoon and into this evening. See
recently issued Mesoscale Discussion 1666 and Severe Thunderstorm
Watch 536 for more details on the short-term threat across this
area. The potential for development farther south into central
MS/AL/GA remains less certain, but still possible.

No changes have been made to the risk areas across parts of the Mid-Atlantic/New England and the southern/central High Plains.

..Gleason.. 07/21/2023

.PREV DISCUSSION... /ISSUED 1116 AM CDT Fri Jul 21 2023/

...AR into the Southeast States...
A large MCS that tracked across southern OK last night is now over northern/central AR. This system and its attendant MCV will move
into western TN this afternoon, where sufficient heating and a very
moist air mass will support the potential for re-intensification.
If this scenario occurs, locally damaging wind gusts would be the
main concern.

To the southeast of the MCS, a weak surface boundary extends across
southeast AR into portions of MS/AL/GA. A very unstable air mass
will become established this afternoon along this axis, where
scattered thunderstorm development is expected. MLCAPE values
around 3000 J/kg will combine with winds in the 5-7km layer around
30 knots to pose some risk of damaging wind gusts in the stronger
cells. The risk of wind damage will increase later this afternoon
if sufficient thunderstorm coverage can result in more organized
outflows.

...New England...
An upper trough is moving across the northeast states today, with an
associated cold front currently extending across parts of eastern
NY/PA. Clouds have been clearing ahead of the front across western
New England, where temperatures will rapidly warm into the 80s.
Ample low-level moisture is present from southern VT/NH southward,
where upper 60s/lower 70s dewpoints will yield afternoon MLCAPE
values of 1500-2000 J/kg. Forecast soundings show sufficient deep
layer shear for a few organized/rotating storms capable of
strong/damaging wind gusts and perhaps hail for a few hours this
afternoon.

...Northeast NM...
Weak easterly low-level upslope flow is present today over northeast
NM, helping to transport 60s dewpoints westward toward the higher
terrain. Thunderstorms are expected to form in the mountains near
Raton and drift southeastward through the afternoon. Steep
low-level lapse rates and 30-40 knots of effective shear will
promote the development of a few supercells capable of large hail
and damaging wind gusts.

$$
--- SBBSecho 3.14-Linux
* Origin: Ilink: CCO - capitolcityonline.net (454:1/105)

ACUS01 KWNS 221257
SWODY1
SPC AC 221255

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0755 AM CDT Sat Jul 22 2023

Valid 221300Z - 231200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE CENTRAL
PLAINS AND SOUTHEAST...

...SUMMARY...
Strong to severe thunderstorms capable of large hail and damaging
winds are expected later today into this evening across the central
Plains to Upper Midwest, while other severe storms will be possible
across the Southeast States and southern Arizona.

...South-central Plains/Mid-Missouri Valley/Upper Midwest...
Weak height rises are expected owing to the building Western States
upper ridge as a belt of moderately strong northwesterly winds aloft
otherwise prevails across these regions. A moist airmass will remain
in place particularly across the south-central Plains and middle
Missouri Valley near and to the southeast of a weak front/wind shift
and a subtle surface wave across Minnesota.

Multiple preferred corridors of potential severe storm development
into this afternoon are probable, including Minnesota as well as
southern Nebraska and northwest/western Kansas near the
aforementioned boundaries, aided by subtle southeastward-moving
perturbations located across eastern Montana and southern Manitoba
early this morning. A regionally maximized combination of moderate
to locally strong buoyancy and 30-40 kt effective shear is expected
by peak heating across southern Nebraska and western/northern
Kansas, where isolated/widely scattered supercells capable of large
hail may occur aside from some persist southeastward-moving small
clusters capable of damaging winds through evening.

Across the Upper Midwest, even with more modest buoyancy (1000-1500
J/kg MLCAPE) and weaker deep-layer shear, some storms capable of
hail/damaging winds will be possible across southern/eastern
Minnesota and western Wisconsin.

Additional storm development is expected by late afternoon/early
evening across the Raton Mesa vicinity and possibly into the nearby Texas/Oklahoma Panhandles. Wind profiles could support some brief
supercell structures with any development across/into the
Panhandles, but south/southeastward-moving clusters are otherwise
expected across the region with some hail and severe-caliber wind
gusts possible through evening.

...Southeast States...
A belt of cyclonically curved and moderately strong westerlies will
continue to reside across the region today. A surface wave will
persist and potentially somewhat deepen across the coastal Carolinas
today, while a west/southwestward-extending front otherwise settles
southward across Louisiana-Mississippi-Alabama-Georgia. A very moist
air mass near/south of the front will steadily destabilize today,
with the strongest destabilization /3000+ J per kg MLCAPE/ expected
across downstate portions of Louisiana-Mississippi-Alabama-Georgia.
With seasonally strong westerlies aloft at least partially atop the
frontal zone, effective shear of 30-35 kt will allow for scattered
sustained multicells and well-organized clusters as storms increase
in coverage and intensity into the afternoon. Damaging winds are the
most probable hazard this afternoon and early evening.

...Southern Arizona...
Clouds may linger particularly during the first part of the day, but
a moderately moist airmass and ample heating will allow for the
boundary layer to destabilize into the afternoon with thunderstorm
development expected especially across southeast Arizona
mountains/higher terrain, and to some extent across the Rim. A
modest strengthening of easterly mid-level winds may occur late
today on the immediate southern periphery of the upper ridge, which
would be favorable for storm propagation onto the desert floor, with
the potential for strong gusty outflow winds and blowing dust.

..Guyer/Mosier.. 07/22/2023

$$
--- SBBSecho 3.14-Linux
* Origin: Ilink: CCO - capitolcityonline.net (454:1/105)

ACUS01 KWNS 241952
SWODY1
SPC AC 241950

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0250 PM CDT Mon Jul 24 2023

Valid 242000Z - 251200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE
NORTHEAST AND THE OHIO VALLEY...

...SUMMARY...
Severe thunderstorms associated with strong wind gusts will be
possible into these evening across parts of the Northeast states and
the Ohio Valley.

...20z Update...

A small southward expansion to the Marginal risk (level 1 of 5) over
TN has been made to account for a developing cluster over southeast
MO and potential for that cluster to continue south/southeast
through early evening. Reference MCD 1697 for short term details on
this severe risk. The Slight risk (level 2 of 5) as also been
expanded westward across parts of southern IN, central/western KY
and northwest TN to account for ongoing observational trends.
Reference MCD 1695 and WW 545 for more information.

Otherwise, the Marginal risk has been trimmed across much of MO into
parts of IL where morning convection has resulted in stronger
inhibition and lowered severe potential.

Reference MCDs 1696 and WW 544 for more information regarding short
term severe potential across the Northeast.

..Leitman.. 07/24/2023

.PREV DISCUSSION... /ISSUED 1122 AM CDT Mon Jul 24 2023/

...Northeast...
Morning water vapor loop shows a series of shortwave troughs over western/central NY and Lake Ontario. Lift ahead of these systems
will promote the development of scattered thunderstorms across parts
of NY/PA, spreading eastward into VT. Forecast soundings show
relatively steep low-level lapse rates and sufficient westerly flow
above 3km to help organize the stronger cells and pose a risk of
damaging wind gusts. Please refer to MCD #1694 for further details.

...OH Valley...
A moist low-level air mass is present today from southern OH
westward into IN/IL/KY with dewpoints in the upper 60s and 70s. A
shortwave trough over WI will approach the area later this
afternoon, with isolated to scattered thunderstorm development
likely. Ample CAPE and sufficient northwest flow aloft will result
in a few strong/severe storms capable of damaging wind gusts. A
consensus of 12z guidance shows a higher concentration of storms
over parts of southwest OH and adjacent parts of KY/IN. Therefore a
small SLGT has been added for that region.

...NV/UT/ID/MT/WY...
A large upper ridge is in place today over much of the Great Basin,
with a band of stronger flow extending from NV into UT/ID and WY/MT.
A shortwave trough embedded in this flow over NV will track
northeastward and aid in the development scattered high-based
showers and thunderstorms later today. This activity may pose a
risk of gusty/damaging winds through the evening.

$$
--- SBBSecho 3.14-Linux
* Origin: Ilink: CCO - capitolcityonline.net (454:1/105)

ACUS01 KWNS 251947
SWODY1
SPC AC 251946

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0246 PM CDT Tue Jul 25 2023

Valid 252000Z - 261200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE NORTHEAST...AND OVER PARTS OF THE NORTHERN PLAINS...

...SUMMARY...
Scattered severe wind/hail-producing thunderstorms are possible
across parts of the Northern Plains and the Northeast into this
evening. Isolated severe gusts are also possible over portions of
the Interior West.

...20z Update...

No changes have been made to the outlook with the 20z Update.
Scattered severe thunderstorms will continue to shift east/northeast
across WW 546 the next few hours before moving offshore the Mid-Atlantic/Northeast coast. Additional severe thunderstorms are
expected to develop over the northern Plains in the next few hours.
These storms will shift east/southeast through the evening into
early tonight, producing hail and damaging gusts.

..Leitman.. 07/25/2023

.PREV DISCUSSION... /ISSUED 1129 AM CDT Tue Jul 25 2023/

...Mid Atlantic into southern New England...
A remnant MCV is currently over eastern PA. This feature is
embedded within a larger-scale shortwave trough and associated 40
knot mid-level jet moving into the northeast states. Forcing ahead
of these features is leading to scattered thunderstorm development.
Strong heating across the region, coupled with dewpoints in the 70s
will lead to moderate CAPE values over 2000 J/kg. Sufficient winds
aloft and steep low-level lapse rates will promote locally damaging
wind gusts in the stronger cells through early evening. Storms will
eventually build southward into eastern VA/MD as well.

...Northern Plains...
Water vapor imagery shows a fast-moving shortwave trough over MT/WY.
This feature will emerge into the Plains this afternoon, with large
scale ascent overspreading the Dakotas. As this ascent reaches the
western edge of deeper/richer moisture over central ND/SD,
thunderstorms are expected to rapidly develop. Initial storms will
likely be supercells with a risk of large hail and damaging winds.
Storms should congeal upscale through the evening as they track east-southeastward into southwest MN/western IA with a continued
risk of damaging winds.

Other more isolated severe storms may develop southward into parts
of NE and northeast CO, with a localized risk of damaging winds and
hail.

$$
--- SBBSecho 3.14-Linux
* Origin: Ilink: CCO - capitolcityonline.net (454:1/105)

ACUS01 KWNS 262003
SWODY1
SPC AC 262002

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0302 PM CDT Wed Jul 26 2023

Valid 262000Z - 271200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS PORTIONS OF THE
SOUTHERN GREAT LAKES REGION...

...SUMMARY...
Severe thunderstorm gusts remain possible this afternoon and evening
for parts of the southern Great Lakes, along with occasional large
hail. Severe gusts also are possible over parts of the central High
Plains this afternoon.

...20Z Update...
The primary changes to the ongoing forecast were to reduce wind
probabilities in the wake of convection, trim severe probabilities
behind the shortwave trough in the Upper Midwest along with minor
changes to the general thunderstorm area. The remainder of forecast
remains on track with additional thunderstorm development possible
in the southern Great Lakes region as the low-level jet intensifies
later today/tonight.

..Wendt.. 07/26/2023

.PREV DISCUSSION... /ISSUED 1109 AM CDT Wed Jul 26 2023/

...Lower MI and Vicinity...
Multiple strong/severe MCSs are ongoing this morning over western
Lower MI, Lake MI, and southern WI. Two lead bowing clusters of
convection over western Lower MI will likely continue to track
quickly eastward today into a progressively more unstable air mass.
Dewpoints in the mid/upper 60s and relatively strong heating will
yield afternoon MLCAPE values over 2000 J/kg. Mid-level lapse rates
are not particularly steep, but rather strong winds aloft and
mesoscale organization of these clusters will help to pose a risk of
damaging winds across much of central/eastern Lower MI through the
afternoon. The potential also exists for a few supercells to form
ahead of the main bowing structures, posing a risk of hail and a few
tornadoes as well.

Behind the lead convection, another bowing MCS is moving across
southwest WI. These storms are closer to the mid-level vorticity
center and even stronger winds aloft. It is unclear how much
destabilization can occur in the wake of the lead storms, but it
seems plausible that this cluster will also pose a severe risk
through much of the afternoon and evening, traversing a similar
track as the southern lead bowing structure.

...UT to CO/KS/NE...
A corridor of sufficient mid-level moisture is expected to result in
scattered high-based showers and thunderstorms from parts of UT into
northern CO and southern WY today. As the storms over the CO
mountains spread eastward into the plains, they will encounter an
increasingly moist and unstable air mass. A few of these storms may
become severe by late afternoon/evening with damaging winds being
the main concern.

...Southern AZ...
Several 12z HREF members show a cluster of thunderstorms developing
over the higher terrain of southern AZ and spreading northwestward
during the evening. If this scenario unfolds, strong wind gusts
could affect the region.

$$
--- SBBSecho 3.14-Linux
* Origin: Ilink: CCO - capitolcityonline.net (454:1/105)

ACUS01 KWNS 301256
SWODY1
SPC AC 301254

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0754 AM CDT Sun Jul 30 2023

Valid 301300Z - 311200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE CENTRAL/NORTHERN GREAT PLAINS...

...SUMMARY...
Severe-thunderstorm potential should be best organized over parts of
the central/northern Great Plains.

...Synopsis...
In mid/upper levels, a series of convectively generated/enhanced
perturbations in the subtropical easterlies have distorted the longstanding/intense Southwestern anticyclone, reshaping it into a configuration centered over the San Juan Mountains, and extending
from there to southern CA and the northwestern Gulf of Mexico. A high-amplitude ridge -- initially positioned from the high through
the central/northern Rockies -- will shift slightly eastward and
weaken a small amount during the period. A series of low-amplitude
shortwaves is evident in the associated flow, across NV/ID/MT.

The eastern CONUS mean trough persists downstream, with two main
embedded shortwave perturbations:
1. Over the coastal Carolinas and vicinity, forecast to eject
northeastward and removed from areas near land by 00Z.
2. Over the Mid-South/Tennessee Valley region, with prior
convective vorticity enhancement. This feature should shift slowly southeastward in strongly difluent, weakening mid/upper flow, toward
the FL Panhandle and northern FL through the period.

The 11Z surface analysis showed a cold front from oceanic waters
offshore of the Mid-Atlantic, west-southwestward over KY and central
MO, becoming a wavy, quasistationary to slow-moving warm front
across eastern/northern NE, western SD, and east-Central MT, to
another low near BZN. This boundary should move little through the
day across the central/northern Plains, with a moist axis remaining
mostly to its south from KS to SD, then northward over extreme
eastern MT/western ND.

...Northern/central Great Plains...
Isolated to scattered thunderstorms -- some as supercells, but most
organizing fairly early into bands or clusters -- are expected to
develop this afternoon and move eastward to southeastward over the
outlook area. Activity also may form along the front, or a weak
surface trough/confluence axis to its north over northeastern MT.
This convection will initiate as one and perhaps two proximal
shortwave perturbations crest the mean ridge and approach the area.
Any supercells may offer large hail (some 2 inches or more in
diameter) and a marginal tornado threat, while severe wind would be
the greatest hazard from multicellular clusters/bands.

The low-level air mass along and within about 100 nm either side of
the moist axis should maintain 50s to low 60s F surface dewpoints
into diurnal heating, beneath steep midlevel lapse rates. This will
foster a corridor of relatively maximized MLCAPE up and down the central/northern High Plains, with values around 1000-1500 J/kg
possible over parts of central/eastern MT and northeastern WY,
increasing to 2000-3000 J/kg over western SD and west-central NE.
Representing modest speeds veering strongly directionally with
height, low-level hodographs are not expected to be particularly
large, but favorable long, amidst effective-shear magnitudes ranging
from near 60 kt in northern areas to 45-50 kt over NE. This will
favor production of large to significant hail. Hail and
strong-severe downdrafts should be well-maintained to the surface
through strongly mixed subcloud layers with nearly dry-adiabatic
lapse rates.

...Southeast...
Widely scattered to scattered thunderstorms are forecast to develop
near and south of the frontal zone to the Gulf Coast, mainly during
the afternoon to early-evening hours when surface temperatures are
warmest and already weak MLCINH is minimized. The convective
environment will be aided somewhat by subtle large-scale ascent
related to the slowly southeastward-moving, second shortwave trough
described above. Rich low-level moisture abounds in the prospective development/inflow region of these storms, with surface dewpoints
commonly in the upper 60s to mid 70s F, and high PW. Deep-layer
winds will be modest, keeping vertical shear weak, and limiting
storm organization to multicells regulated largely by mesobeta- and smaller-scale effects (such as localized clustering and cold-pool
aggregation). Severe potential appears to be rather poorly focused
and marginal overall, with damaging to isolated severe gusts as the
main concern.

...AZ/Southeastern CA...
Isolated to widely scattered thunderstorms are expected to develop
again this afternoon over higher terrain of southern AZ. Activity
should move approximately westward over adjoining desert floors
through the remainder of the afternoon and into the evening, where
deeply mixed subcloud layers will support strong-severe downdrafts.
Storm organization and persistence may be more than previous days,
owing to slightly deeper/stronger gradient flow aloft north of the
Mexican height weakness, and to larger inflow-layer moisture content
for greater buoyancy (MLCAPE potentially 500-1000 J/kg).

..Edwards/Broyles.. 07/30/2023

$$
--- SBBSecho 3.14-Linux
* Origin: Ilink: CCO - capitolcityonline.net (454:1/105)

ACUS01 KWNS 010540
SWODY1
SPC AC 010539

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1239 AM CDT Tue Aug 01 2023

Valid 011200Z - 021200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE
NORTHERN PLAINS...

...SUMMARY...
Severe thunderstorms capable of producing large hail and damaging
winds are expected Tuesday across parts of North Dakota into
northern Minnesota. A few strong/severe storms are also expected
across the central High Plains into the mid Missouri Valley.
Thunderstorms capable of producing occasional damaging winds may
also occur over parts of the coastal Southeast.

...Northern Plains...

Water-vapor imagery depicts a ridge-topping short-wave trough
ejecting east across AB/SK region early this morning. This feature
is forecast to dig southeast and should progress into northwest
ON/Arrowhead of MN by the end of the period. While appreciable
height changes are not expected south of the international border,
it appears this short wave will encourage deep convection
downstream. Latest model guidance suggests low-level warm advection
ahead of the short wave/surface front will spread south across MB
into northern MN by 18z. This activity could evolve into an MCS as
it propagates south along a corridor of warm advection.

Additionally, strong boundary-layer heating will occur across the
northern Plains, extending across ND into eastern MT. This will
ensure CINH weakens by late afternoon along the southward-moving
surface front that should extend from southern MB-northern
ND-northeast MT by late afternoon. This boundary will focus
additional thunderstorm development as temperatures warm through the
lower 90s. Forecast soundings exhibit modest 500mb flow, but
low-level shear should remain weak. While some early-day weak
convection may drift across the SK border into the US, surface
heating is expected to be the primary mechanism for renewed
convective development by 21-23z along the boundary. Large hail and
gusty winds are the expected threats.

...Central Plains/Mid MO Valley...

Early-day MCS will likely be ongoing at the start of the period over
the lower MO Valley. This activity will be supported by low-level
warm advection as 850mb west-southwesterly flow is forecast across
eastern KS into northwestern MO at daybreak. LLJ is expected to
weaken during the day, and high-res models subsequently allow this
activity to weaken. It's not entirely clear how soon convection will
weaken but convective debris and showers will likely linger across
much of MO through the period. However, strong surface heating
across much of KS will allow surface temperatures to warm to near
100F. Convective temperatures will be breached with these readings,
and isolated thunderstorms may redevelop along the old convectively
reinforced boundary that will be draped from southwest MO-northern
KS-eastern CO. Scattered storms will also evolve over CO which will
spread downstream into an air mass seemingly favorable for
supporting at least gusty winds and some threat for hail.

...Southeast...

Low-level convergence corridor will likely extend from northeast FL
to the Carolina Coast. Scattered convection should develop early in
the period then spread south within strengthening northwesterly
mid-level flow in the wake of the east-coast trough. Modest lapse
rates and high PW values suggest gusty winds are the primary
concern.

..Darrow/Bentley.. 08/01/2023

$$
--- SBBSecho 3.14-Linux
* Origin: Ilink: CCO - capitolcityonline.net (454:1/105)

ACUS01 KWNS 020543
SWODY1
SPC AC 020542

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1242 AM CDT Wed Aug 02 2023

Valid 021200Z - 031200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM CENTRAL MO
INTO SOUTHERN IL...

...SUMMARY...
Thunderstorms capable of producing damaging gusts, isolated hail,
and possibly a tornado are possible from central Missouri into
southern Illinois, mainly this afternoon and evening. Isolated
strong to severe thunderstorms are also possible across the Upper
Great Lakes region and central High Plains.

...Missouri into southern IL and vicinity...
Another round of widespread elevated convection will likely be
ongoing at the start of the period from MO into southern IL and
vicinity, as a southwesterly low-level jet impinges upon a
persistent baroclinic zone. This convection may tend to diminish
somewhat by late morning/early afternoon, potentially allowing for
several hours of diurnal heating and outflow modification, and
development of moderate to locally strong buoyancy by late
afternoon.

Meanwhile, an MCV originating from the central High Plains is
forecast to approach the lower MO River Valley during the afternoon
and evening, resulting in renewed thunderstorm development near and
to the cool side of an outflow-reinforced surface boundary. Modestly
enhanced low/midlevel flow will support sufficient effective shear
for organized convection, and supercells may evolve out of initial redevelopment within a moist and moderately unstable environment.
The extent of enhancement to low-level shear/SRH remains uncertain,
but may be sufficient to support a tornado or two, depending in part
on the extent of outflow modification to the cool side of the
boundary. A threat for isolated damaging wind and hail would also
accompany any sustained supercells.

With rather weak upper-level flow across the region and potential
for storm interactions/mergers, a rather quick transition to
outflow-driven clusters may occur by early evening, potentially
spreading a damaging-wind threat southeastward toward the lower OH
Valley before convection weakens late tonight.

...Upper Great Lakes vicinity...
Diurnal heating of a relatively moist environment is expected to
result in moderate destabilization this afternoon from MN into parts
of the upper Great Lakes. Meanwhile, modest northwesterly midlevel
flow will support effective shear of 30-40 kt, conditionally
favorable for organized convection. However, large-scale ascent may
be relatively limited, with a shortwave mid/upper-level trough
forecast to pass well to the north across Ontario, and the trailing
cold front not expected to approach the area until tonight. As a
result, storm coverage may remain limited, but development of
isolated cells/clusters will be possible during the
afternoon/evening as MLCINH weakens. Hail and locally damaging gusts
will be the primary threats with any sustained stronger storms.

...Central High Plains...
Relatively rich low-level moisture will again support moderate
destabilization across parts of the central High Plains this
afternoon, and scattered thunderstorm development is expected from
eastern CO into adjacent portions of southwest NE and western KS.
Deep-layer shear is expected to remain rather weak, but isolated
severe outflow gusts will be possible, especially in areas where
stronger pre-convective heating occurs.

..Dean/Bentley.. 08/02/2023

$$
--- SBBSecho 3.14-Linux
* Origin: Ilink: CCO - capitolcityonline.net (454:1/105)

ACUS01 KWNS 040602
SWODY1
SPC AC 040600

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0100 AM CDT Fri Aug 04 2023

Valid 041200Z - 051200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE
NORTHEAST AND CENTRAL PLAINS...

...SUMMARY...
Severe thunderstorms are possible across parts of the Northeast and
also the central High Plains this afternoon and evening, with a
threat of damaging wind and isolated hail. Additional strong storms
are possible along a broad arc from the central Plains to the
Southeast.

...Northeast...
A mid/upper-level cyclone is forecast to remain centered over Quebec
today, as small-scale vorticity maxima move through the attendant
trough across parts of the Northeast. A weak cold front will move
southeastward across the region this afternoon and evening. Moderate destabilization will support scattered thunderstorm development
along/ahead of the front through the afternoon, with moderate
mid/upper-level flow resulting in sufficient effective shear for
some storm organization. Initial semi-discrete storms will be
capable of producing at least isolated hail and damaging gusts, with
some tendency for clustering and a transition to primarily a
damaging-wind threat by late afternoon/early evening. Some threat
may approach near-coastal areas before storms weaken later tonight.

...MO/AR into parts of the Southeast...
Multiple clusters of thunderstorms will likely be ongoing later this
morning from parts of MO/AR into the Southeast, as a west to
west-northwesterly low-level jet impinges upon an outflow-reinforced
baroclinic zone. These clusters may pose at least an isolated
damaging-wind threat as they move southeastward during the day, with
a somewhat greater coverage of wind damage possible in areas where
stronger preconvective diurnal heating/destabilization can occur.
Isolated hail also cannot be ruled out, especially where buoyancy is
stronger across parts of MO/AR. Storms may also intensify near a
remnant MCV across northern MO this afternoon and spread
southeastward this evening, with at least an isolated severe
wind/hail threat.

In general, rather weak deep-layer flow/shear will tend to limit
storm organization, and the most favored corridors for somewhat
greater damaging-wind potential (and possible eventual upgrade from
5% wind probabilities) will be dependent on mesoscale details that
remain unclear at this time.

...Central Plains...
Thunderstorm development is again expected across portions of the
central High Plains late this afternoon into this evening, within a
moderately unstable and modestly sheared environment. Storm coverage
may be somewhat greater from southwest SD into western NE, in closer
proximity to a persistent mid/upper-level trough, though isolated to
widely scattered development will be possible into parts of eastern
CO and western KS. With modest westerly flow aloft, effective shear
will likely remain in the 25-35 kt range (higher where winds are
locally backed), sufficient for a few strong multicells and perhaps
a marginal supercell or two. Large hail and localized severe gusts
are expected to be the primary threats.

Guidance varies regarding the extent (if any) of nocturnal low-level
jet intensification later tonight across the central Plains, which
will impact the potential for any organized upscale growth, but some
threat for isolated severe gusts could spread eastward somewhere
across the central Plains late tonight.

..Dean/Moore.. 08/04/2023

$$
--- SBBSecho 3.14-Linux
* Origin: Ilink: CCO - capitolcityonline.net (454:1/105)

ACUS01 KWNS 061249
SWODY1
SPC AC 061248

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0748 AM CDT Sun Aug 06 2023

Valid 061300Z - 071200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS MID-MS AND LOWER
OH VALLEYS TO THE MID-SOUTH AND SOUTHEAST...

...SUMMARY...
A few tornadoes along with scattered damaging winds and large hail
will be possible from late afternoon into tonight from the
Mid-Mississippi to Lower Ohio Valleys. Scattered damaging winds will
also be possible, mainly from midday into early evening across parts
of the Mid-South and Southeast.

...Mid-MS to Lower OH Valleys...
In the wake of decaying convection over northeast MO and AR/OK, a
plume of at least moderate buoyancy should develop towards peak
heating across the Mid-MS Valley. Guidance is fairly consistent that
an arc of thunderstorms will develop during the mid to late
afternoon across southeast IA into northeast MO downstream of the eastward-drifting shortwave trough and attendant surface cyclone
over the Mid-MO Valley. The impinging of a 700-mb speed max across
MO into IL will enhance 0-3 km SRH and foster supercell development
despite predominantly west-southwesterly low-level flow. Modest
mid-level lapse rates (especially with eastern extent) may curtail
greater updraft intensity. But with at least a few supercells
expected, there will be potential for large hail up to around 2
inches and a couple tornadoes. Towards late evening, upscale growth
into one or two organized clusters seems plausible, with potential
for an MCS to evolve along the northern extent of the surface-based
instability plume. An elongated swath or two of damaging winds with
embedded severe gusts, along with a couple brief tornadoes may be
sustained into the early overnight into the Lower OH Valley.

...Mid-South to the Southeast...
There is uncertainty whether a decaying MCS near the AR/OK border
will completely subside by late morning owing to nearly cloud free
insolation underway downstream of its remnant outflow. This boundary
will likely serve as a focus for renewed thunderstorm development
from midday through the afternoon as it spreads east of the Lower MS
Valley into the Southeast. While the leading outflow will outpace
stronger mid-level flow attendant to the slow-moving trough over the
Mid-MO Valley, impinging of 25-35 kt 700-mb westerlies from the TN
Valley northward should be adequate to support semi-organized
multicell clusters amid an extensive plume of large buoyancy across
the Deep South. Scattered damaging wind swaths from water-loaded
downbursts will be possible through early evening. Have expanded
both the cat 1 and 2 risks southward to account for a more southern
evolution of clusters.

During the evening, low-level warm theta-e advection should
strengthen along the trailing outflow/effective baroclinic zone over
the Mid-South. This activity should pose an isolated threat for
severe hail initially before likely clustering into a localized
damaging wind threat overnight.

...Central/southern Rockies...
The presence of 50s surface dew points will support potential for
isolated but regenerative thunderstorms to develop along the Front
Range during the late afternoon and evening. While the NAM appears
much too cool across the adjacent plains, MLCIN should steadily
increase with eastern extent. This should yield a rather confined
corridor for weak buoyancy with MLCAPE of only 500-1000 J/kg.
Nevertheless, deep-layer wind profiles will be quite favorable for
supercells and large hail potential given near-perfectly
straight-line hodographs. After collaboration with WFOs PUB/BOU have
held at upgrading to a cat 1-MRGL risk for now, but a meso-beta
scale corridor of cat 2-SLGT risk for hail may be warranted in later
outlooks.

Downstream of a minor shortwave trough over the interior Northwest,
isolated to scattered afternoon thunderstorms are anticipated around
the UT/WY/CO border area within a weak buoyancy plume. Adequate
deep-layer shear will exist for a threat of marginally severe hail
and wind centered on the late afternoon.

...Central/southern Appalachians to Lake Erie...
A trio of MCVs, one over northern IN and the others over eastern
KY/TN, will aid in scattered thunderstorm development downstream of
these features from midday through the afternoon. Instability will
be substantially weaker relative to the TN Valley region, owing to
both weaker mid-level lapse rates and buoyancy. Pockets of stronger
low to mid-level flow attendant to these MCVs may support sporadic
localized damaging winds.

..Grams/Broyles.. 08/06/2023

$$
--- SBBSecho 3.14-Linux
* Origin: Ilink: CCO - capitolcityonline.net (454:1/105)

ACUS01 KWNS 101244
SWODY1
SPC AC 101242

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0742 AM CDT Thu Aug 10 2023

Valid 101300Z - 111200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS EASTERN NC/FAR
SOUTHEAST VA AND PARTS OF THE UPPER MIDWEST INTO NORTHEAST NE...

...SUMMARY...
Mainly isolated severe thunderstorms are expected over parts of the
eastern and central states this afternoon into tonight. The most
probable areas for potentially scattered coverage are across the
eastern North Carolina/southeast Virginia vicinity and parts of the
Upper Midwest into northeast Nebraska.

...Eastern NC/southeast VA vicinity...
A broad swath of convection persists from southwest VA across
northern parts of GA to MS. This convection was progged by some
guidance to deteriorate east of the southern Appalachians but has
failed to do so as renewed development has recently occurred over
upstate SC within a low-level warm advection regime. A remnant MCV
near the TN/NC/VA border area should track into coastal southeast VA
by early to mid-afternoon. It seems increasingly likely that morning
convection will spread east across eastern NC and southeast VA ahead
of stronger boundary-layer destabilization and this should serve to
marginalize the overall severe threat.

There is still a conditional scenario where convective redevelopment
occurs during the late afternoon ahead of a secondary shortwave
impulse moving east from the TN Valley. With a 50-55 kt 500-mb
jetlet centered across eastern NC during this time frame, deep-layer
shear profiles would be conducive to a few supercells. If this
occurs, overall spatial extent of this threat will likely be more
limited than previously forecast. Conditionally, a tornado or two,
and a swath of damaging winds along with isolated severe hail remain
possible.

...Upper Midwest to eastern NE...
As a mid/upper ridge shifts east, a low-amplitude trough will
overspread the northern Great Plains. This will help induce a weak
surface cyclone over western ND with a surface trough arcing south
into central NE and a warm front extending southeast through
southern MN. Relatively modest boundary-layer moisture and
deep-layer shear will be limiting factors to a more prolific severe
threat across the region. But steeper mid-level lapse rates within
an elevated mixed layer will spread east across most of SD and much
of NE by early evening and support a confined corridor of moderate
buoyancy with MLCAPE of 1000-2000 J/kg. Effective bulk shear of
25-35 kts should support a mixed mode of a few supercells and
multicell clusters.

The most likely zone for scattered thunderstorm development in the
late afternoon should be near the surface trough/warm front
intersection in the northeast SD border area with ND/MN.
Increasingly isolated development should trail south along the
trough. A mix of large hail and severe wind gusts will be the main
threats, likely becoming more marginal in terms of
intensity/coverage with eastern extent into MN/IA, especially after
sunset as convection becomes increasingly elevated.

...Mid-South/TN Valley...
Convectively reinforced outflow from lingering thunderstorms this
morning should serve as a focus for redevelopment later this
afternoon. Another round of low-level warm theta-e advection driven
storms should occur after sunset tonight. A modest combination of
mid-level lapse rates and vertical shear should support a mainly
isolated severe threat, with sporadic instances of damaging gusts
and marginal hail.

...Coastal Mid-Atlantic to southern New England...
Low-level warm theta-e advection will strengthen today and translate
northeast from the Mid-Atlantic across New England this afternoon
and evening. Low-topped convection should eventually develop amid
meager surface-based instability as thermodynamic profiles become
saturated. Potential for a brief tornado exists owing to enlarged
low-level hodograph curvature, but this probability appears to be
rather low.

...Central High Plains...
Isolated high-based thunderstorms should develop off the higher
terrain of southeast WY and far north-central CO near a lee surface
trough. A deep mixed boundary layer along the adjacent High Plains
could support a few severe wind gusts during the late afternoon to
early evening.

...West-central/northwest TX...
Hot surface temperatures along the dryline may support isolated late
afternoon to early evening thunderstorm development. Should deep
convection become sustained, the very deeply mixed boundary layer
could yield a few severe wind gusts.

..Grams/Dean.. 08/10/2023

$$
--- SBBSecho 3.14-Linux
* Origin: Ilink: CCO - capitolcityonline.net (454:1/105)

ACUS01 KWNS 110551
SWODY1
SPC AC 110549

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1249 AM CDT Fri Aug 11 2023

Valid 111200Z - 121200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE MID AND
UPPER MISSISSIPPI AND LOWER MISSOURI VALLEYS...

...SUMMARY...
Severe thunderstorms capable of large hail, damaging gusts, and
perhaps a tornado or two are possible across portions of the Mid and
Upper Mississippi Valley and Lower Missouri Valley areas today.

...Synopsis...
A shortwave trough across the northern Plains will intensify as it
moves into the Upper Midwest today. Across the southern Plains,
ridging aloft will modestly increase. At the surface, a low will
move through the Upper Midwest along with its parent trough. An MCV
is expected to move through Iowa into northern Illinois/southern
Wisconsin early in the period. An outflow boundary from this
activity will lie roughly east-west near the Missouri-Iowa border
into parts of central/northern Illinois. Farther northwest, a cold
front will move south and east through the day. A remnant boundary
will also remain in the Southeast.

...Eastern Iowa...southern Wisconsin...northern/central Illinois...
The most complex portion of the forecast will be the evolution of
the MCV. The character of the convection associated with this
feature remains rather loosely organized Thursday night. By this
morning, additional boundary-layer stabilization is likely to weaken
this activity further as it reaches the Mississippi River. Some reintensification can occur as the boundary layer tries to warm this morning/early afternoon, but cloud cover moving downstream of the
MCV does not lend much confidence in this scenario. A secondary
possibility is that storms could from along the outflow during the
afternoon. This activity would be more likely to impact parts of
central Illinois. However, convergence along this boundary appears
weak and deep-layer ascent is also minimal. Should one of these
scenarios play out, damaging winds and perhaps a brief tornado would
be possible. A categorical Slight will be maintained this outlook
despite the described uncertainties.

...Mid-Missouri/Mid-Mississippi Valleys...
Strong buoyancy is expected to develop south of the outflow
boundary. Northwesterly flow aloft will contribute to 40-50 kts of
effective shear across this boundary. This environment will support
supercells capable of large hail and strong to severe wind gusts.
The main uncertainty with this activity will be the overall coverage
of storms during the afternoon due to weak forcing for ascent.
Capping appears evident on forecast soundings during the afternoon.
By late afternoon/early evening, the front will approach the region
along with an increase in the low-level jet. Storm initiation will
become more likely into the evening due to these factors. While
storms could be slightly elevated by that point, large hail and
perhaps more isolated wind damage would remain threats.

...Minnesota/Wisconsin...
Lingering moisture and strong heating behind the cold front will
promote convective development along with the passage of the
shortwave trough. Moderate northwest flow at mid levels will
increase effective shear to 40-45 kts by the afternoon. With cold
temperatures aloft and long hodographs, widely scattered to
scattered storms will be capable of large hail and wind damage.

...Southeast...
Though shear will not be overly strong, a very moist airmass and
modestly steep mid-level lapse rates will promote MLCAPE on the
order of 3000-4000 J/kg. Wind damage from downbursts will be the
primary risk. A corridor or two of more organized wind damage
potential could develop as cold pools congeal, but predictability on
where this will occur is low.

..Wendt/Lyons.. 08/11/2023

$$
--- SBBSecho 3.14-Linux
* Origin: Ilink: CCO - capitolcityonline.net (454:1/105)

ACUS01 KWNS 141253
SWODY1
SPC AC 141252

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0752 AM CDT Mon Aug 14 2023

Valid 141300Z - 151200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF
KENTUCKY AND TENNESSEE...EXTENDING EASTWARD TO THE MID-ATLANTIC
REGION...

...SUMMARY...
Strong/locally severe thunderstorms are expected today and into this
evening across portions of the Midwest, Kentucky and Tennessee,
extending eastward to the Mid-Atlantic Region.

...Synopsis...
In mid/upper levels, ridging will persist from the Pacific Northwest
to the southern High Plains, then eastward over the Gulf Coast
States. However, highest heights will shift from the Gulf and
Pacific Northwest regions into areas of the central Rockies to
northern Great Basin, where a col has been noted between lows over
the Upper Midwest and Pacific near southern CA. This will occur as
the former low -- apparent in moisture-channel imagery over
southwestern MN -- continues digging southeastward across IA,
reaching northwestern IL by 00Z. By then, the accompanying through
should extend across portions of WI, MO and OK, before reaching an
axis near MBS-EVV-PAH-JBR around 12Z.

At the surface, 11Z analysis showed an occluded low over southern
MN, related to the northern-stream trough, with separate triple-
point low near STL. A cold front was drawn from there southwestward
over southern MO, southeastern OK, parts of north-central/west-
central TX, and southeastern NM. A warm front extended over
southern parts of IL/IN to southern WV, becoming quasistationary
over central VA. The warm front will move northward over more of
WV/VA through the afternoon. By 00Z, the triple point low should
reach the PKB area, with cold front across eastern parts of KY/TN,
northern parts of AL/MS, northern LA, and south-central/southwest
TX. By 12Z, with a low in the corridor from northeastern PA to near
NYC, the cold front should extend across southeastern PA, northern/
western VA, western NC, northern GA, and southern MS, while
decelerating over south TX.

...Mid-Atlantic to TN/KY...
Several episodes of strong-severe thunderstorms are possible across
this corridor, with enough spatial overlap between them to warrant
maintaining a continuous area of severe probabilities similar to
those outlined in the previous outlook.

A broad area of ongoing precip with embedded thunderstorms --
initially over portions of KY/TN -- largely should remain non-severe
while shifting eastward into the central Appalachians today.
However, increasing deep-layer flow and favorable low-level moisture
will precede the associated UVV plume, along with muted diurnal
heating of a moist airmass with weak CINH from parts of WV across
the nearby Blue Ridge and Piedmont of VA, eastward toward Chesapeake
Bay and over the Delmarva Peninsula. This may support strong-severe
gusts and hail with thunderstorms forming during the afternoon over
higher terrain and shifting eastward to northeastward toward the
coast. Of note: progs with RAP basis -- including HRRR -- appear
to be mixing and drying the boundary layer excessively over the
Piedmont and coastal plain, leading to potential underproduction
and/or muting of convection.

After several hours of warm advection and increasing surface heating
behind the morning activity, the best organized overall severe
threat should develop this afternoon from parts of middle/eastern TN
to southern OH/WV, and shift eastward over the adjoining
Appalachians. MLCAPE should range from around 2000-3000 J/kg across middle/eastern TN -- where strongest heating/recovery is probable
but deep flow/shear somewhat weaker -- to around 500-1000 J/kg near
the Ohio River and northern WV. Effective-shear magnitudes around
40-50 kt should be common over eastern KY and WV, with modest 0-1-km
SRH but around 150-250 J/kg effective SRH. This suggests an
eastward-moving corridor of convection containing blend of
supercells, multicell clusters and quasi-linear segments with
sporadic bow/LEWP features will be possible, with accompanying
threat for damaging to severe gusts, isolated hail, and at least marginal/conditional tornado potential.

The northern part of this convective plume may persist overnight
into an airmass east of the mountains -- across parts of the
Piedmont and coastal plain of the Mid-Atlantic -- supportively
recovered via theta-e advection from any earlier activity not far to
the south and east. The parameter space should be favorable for
severe well after dark, with 40-50 kt effective-shear magnitudes,
locally enlarged hodographs with 200-300 J/kg effective SRH, and
around 1000-2000 J/kg MLCAPE. Convective coverage is uncertain, but
all hazards will be possible.

...Portions of the Midwest...
Scattered thunderstorms should develop from midday through the
afternoon, in a broad arc extending from just southeast of the
occluded low toward the eastward-moving triple point, along/ahead of
a combined occluded front/inverted trough. This activity should
shift eastward to northeastward across the northwestern spur of the
"marginal" outlook area, offering isolated severe hail, damaging
gusts, and perhaps a tornado or two.

With abundant clouds and some areas of precip possible across the
region, diabatic heating will be present but considerably muted.
Nonetheless, a combination of warm advection just ahead of the
occluded front, and midlevel DCVA/cooling preceding the strong
shortwave trough, will contribute to development of modest but
adequate surface-based buoyancy, prior to frontal passage. Modified
forecast soundings suggest surface dewpoints in the 60s F supporting
MLCAPE generally in the 500-1000 J/kg range. Mid/upper-level flow
and deep shear will increase southeastward across the region, away
from the immediate vicinity of the mid/upper trough, despite the
presence of weak low-level flow. Still, effective-shear magnitudes
mostly below 35 kt should limit organized severe potential to
marginal levels by the time the boundary layer destabilizes enough
for surface-based parcels.

..Edwards/Dean.. 08/14/2023

$$
--- SBBSecho 3.14-Linux
* Origin: Ilink: CCO - capitolcityonline.net (454:1/105)

ACUS01 KWNS 150547
SWODY1
SPC AC 150546

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1246 AM CDT Tue Aug 15 2023

Valid 151200Z - 161200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM PORTIONS OF
CENTRAL AND EASTERN NORTH CAROLINA NORTHEASTWARD TO NEW JERSEY...

...SUMMARY...
Strong to severe thunderstorms are forecast this afternoon and
evening from southern New England into the Southeast, and over the
lower Great Lakes vicinity. Highest severe-thunderstorm coverage is
expected from the southern Delmarva vicinity into North Carolina.

...Southern New England to the Southeast...
A cold front -- trailing from a low progged to lie across the
northern New Jersey vicinity -- will shift gradually eastward across
the East Coast states, and southeastward across the Southeast,
through the afternoon and evening hours. Daytime heating of the
moist pre-frontal boundary layer will result in ample
destabilization to support isolated to scattered storm development
by early afternoon. With a belt of enhanced low- to mid-level
southwesterlies, locally organized storms are expected to evolve,
some capable of producing severe-caliber hail and/or strong wind
gusts near severe levels. Greatest risk appears likely to evolve
during the late afternoon hours, from southern New Jersey to North
Carolina, where the most favorable CAPE/shear overlap should reside.
Afterward, storms should begin to diminish into the evening with the
onset of diurnal cooling, with any remnant convection then moving
offshore overnight.

...Lower Great Lakes region...
As an upper trough advances eastward across the Ohio Valley toward
the Lower Great Lakes region, daytime heating beneath cooling
mid-level temperatures will support modest destabilization.

Though surface reflection of the upper system will remain weak,
ascent should be sufficient to support scattered, low-topped showers
and thunderstorms from northeastern Ohio across the Lower Great
Lakes/Finger Lakes region and into adjacent portions of
Pennsylvania. While limited shear should temper severe potential, a
few stronger storms may become briefly severe, with marginal hail
and gusty winds capable of producing tree damage the primary risks.

..Goss/Lyons.. 08/15/2023

$$
--- SBBSecho 3.14-Linux
* Origin: Ilink: CCO - capitolcityonline.net (454:1/105)

ACUS01 KWNS 160558
SWODY1
SPC AC 160556

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1256 AM CDT Wed Aug 16 2023

Valid 161200Z - 171200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE UPPER MISSISSIPPI VALLEY...

...SUMMARY...
Strong to severe thunderstorms are expected across parts of the
Upper Mississippi Valley during the late afternoon into evening
hours. Severe wind and hail are the main threats, though a tornado
is also possible.

...Synopsis...
A mid-level trough will traverse the Northeast as an upper ridge
remains in place across the Interior West today. Across the northern
Plains into southern Canada, an upper trough will amplify, prompting
rapid deepening of a surface low across Manitoba/Ontario. Strong lee
troughing and an associated cold front will trail the surface low
and sweep across the Upper MS Valley late this afternoon through the
overnight. Ahead of this cold front, adequate boundary-layer
destabilization will occur amid strong vertical wind shear,
supporting the development of strong to severe thunderstorms,
especially by late afternoon onward.

...Upper MS Valley...
Though high-level cloud cover may overspread much of the Upper MS
Valley during the day, adequate surface heating should still support
surface temperatures rising into the 80s F amid low to perhaps mid
60s F dewpoints. 8+ C/km mid-level lapse rates overspreading the
warming boundary layer will boost SBCAPE to 2500-4000 J/kg in spots.
The cold front will be preceded by a 50+ kt southwesterly 850 mb jet
as a 70+ kt west-northwesterly 500 mb speed max approaches the Upper
MS Valley, contributing to strongly curved and elongated hodographs
and well over 50 kts of deep-layer shear. However, relatively strong
capping will also precede the cold front, with strong forcing along
the front itself serving as the primary focus for convective
initiation. Some brief, transient supercellular development is
possible, with large hail and perhaps a tornado possible with any
storms that can avoid being undercut by the cold front for any
appreciable period of time. However, the strong forcing will likely
encourage linear convective development by late afternoon into early
evening, with severe wind and occasional bouts of hail being the
primary concerns.

...Southeast into the FL Peninsula...
Strong heating of a boundary layer, characterized by deep and rich
moisture, will encourage the development of pulse-cellular storms
and perhaps multicellular clusters (where cold-pool mergers can
occur) during the afternoon. Vertical wind shear will be weak, with
mid-level lapse rates expected to be mediocre (i.e. at or under 6.5
C/km). Nonetheless, mid to upper 80s/70s F surface
temperatures/dewpoints will support SBCAPE over 2000 J/kg. PWATS may
exceed 2 inches in locations, and when considering appreciable CAPE
density profiles, some of the more intense storms may produce
water-loaded downdrafts. A couple of damaging gusts are possible,
warranting the introduction of Category 1 (Marginal Risk)
probabilities.

...Southwest...
Monsoon-driven thunderstorm development is expected by afternoon
peak heating across the Lower Colorado River Basin into the Four
Corners region. Enough instability may encourage strong storm
development, with a severe gust or two possible. At the moment,
severe-gust coverage is expected to be too sparse to warrant severe probabilities this outlook.

..Squitieri/Lyons.. 08/16/2023

$$
--- SBBSecho 3.14-Linux
* Origin: Ilink: CCO - capitolcityonline.net (454:1/105)

ACUS01 KWNS 201941
SWODY1
SPC AC 201939

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0239 PM CDT Sun Aug 20 2023

Valid 202000Z - 211200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS SOUTHEAST
CA INTO THE LOWER CO VALLEY...

...SUMMARY...
A couple tornadoes are possible across the Lower Colorado Valley and
southern Mojave Desert vicinity through around dusk.

...20z Update...

Only minor adjustments have been made to the 2 percent tornado
probabilities over AZ. Otherwise, the previous outlook remains on
track. See previous discussion below for more details, and reference
MCD 2017 for short term severe/tornado hazard information.

..Leitman.. 08/20/2023

.PREV DISCUSSION... /ISSUED 1119 AM CDT Sun Aug 20 2023/

...Desert Southwest...
The conditional TC-tornado environment evident over the northern
Gulf of CA and northwest Sonora is expected to spread
north-northwest across the Lower CO Valley and southern Mojave
Desert vicinity. The primary corridor of concern will be across
southeast CA and adjacent portions of western AZ/southern NV this
afternoon into early evening. Here, meager MLCAPE from 300-600 J/kg
should develop with some thinning of the cloud canopy amid upper 60s
to low 70s boundary-layer dewpoints. This will remain coincident
with an enlarged low-level hodograph in the northeast quadrant of
weakening TC Hilary. Most 12Z HREF guidance struggles to maintain
deep convection, but sustained low-topped convection could acquire
updraft rotation and be capable of producing a brief tornado. This
threat will end from south to north during the evening as low-level
drying and decreasing hodograph curvature occurs within the
southeast quadrant of the remnant TC.

Relatively greater likelihood of deeper convective development is
anticipated during the mid to late afternoon along the differential boundary-layer heating corridor from southeast AZ to southwest UT.
This zone will be within the pronounced west to east gradient of
high to low PW and consequently along the fringe of meager MLCAPE.
At least isolated thunderstorms should form off the higher terrain
and possess progressively weaker low-level SRH relative to the
west/south. Some 12Z HREF members do depict a 2-5 km UH signal which
makes sense given adequate shear within this layer. While mid-level
rotation will be possible, isolated severe wind gusts should be the
primary threat, particularly with any cells/small clusters that can
propagate towards the more deeply mixed environment to the
north-northeast.

$$
--- SBBSecho 3.14-Linux
* Origin: Ilink: CCO - capitolcityonline.net (454:1/105)

ACUS01 KWNS 230532
SWODY1
SPC AC 230531

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1231 AM CDT Wed Aug 23 2023

Valid 231200Z - 241200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE GREAT LAKES AND UPPER OHIO VALLEY...

...SUMMARY...
Thunderstorms associated with damaging wind gusts and hail are
expected to develop tonight across parts of the lower Great Lakes
region and upper Ohio Valley. Marginally severe wind gusts and hail
will also be possible in parts of the northern Plains late this
afternoon and evening.

...Great Lakes/Upper Ohio Valley...
A mid-level anticyclone will be located across the central U.S.
today. On the northeastern periphery of this feature, mid-level flow
will be from the west and northwest across the Great Lakes region. Thunderstorms will likely be ongoing across parts of Lower Michigan
at the start of the period. This activity is expected to weaken by
late morning. A moist airmass will advect eastward across Lower
Michigan today, with surface dewpoints increasing into the lower to
mid 70s F. Within northwest mid-level flow, a shortwave trough is
forecast to move southeast across the eastern Great Lakes. Ahead of
this feature, model forecasts consistently develop scattered
thunderstorms late this evening. This activity is forecast to
organize into an MCS and move southeastward across eastern Lower
Michigan, and into northern Ohio and northwest Pennsylvania during
the overnight period. RAP forecast soundings near the track of the
MCS around midnight suggest that the storms will be surface-based
with strong instability (MUCAPE above 4000 J/kg), and moderate
deep-layer shear. This should support a wind-damage threat as the
MCS develops into a bowing line segment. The MCS could impact areas
as far south as southeast Ohio and western Pennsylvania later in the
period.

...Northern Plains...
Mid-level flow is forecast to be from the west-southwest across the north-central U.S. today, over the top of a mid-level anticyclone in
the central U.S. At the surface, a quasi-stationary front will
remain from central South Dakota into southern Minnesota. Low-level
moisture will be maximized to the north of this boundary from
northeastern South Dakota into central and eastern North Dakota,
where an axis of instability will likely develop. Isolated
thunderstorms may form across parts of North Dakota near this axis
of instability from late afternoon into evening. The storms will
most likely develop along the leading edge of a band of large-scale
ascent ahead of an approaching shortwave trough, with most of the
convection remaining elevated. In spite of this, effective shear
near 40 knots and somewhat steep lapse rates above 700 mb may be
enough for a marginal hail threat. A few strong wind gusts will also
be possible.

..Broyles/Weinman.. 08/23/2023

$$
--- SBBSecho 3.14-Linux
* Origin: Ilink: CCO - capitolcityonline.net (454:1/105)

ACUS01 KWNS 240558
SWODY1
SPC AC 240556

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1256 AM CDT Thu Aug 24 2023

Valid 241200Z - 251200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE GREAT LAKES REGION...

...SUMMARY...
Scattered severe thunderstorms producing damaging winds, large hail,
and perhaps a tornado should occur from mainly late this afternoon
through tonight across parts of the southern Great Lakes region into
the central Appalachians. Some of these winds could be significant
(75+ mph).

...Synopsis...
A large upper-level anticyclone will remain dominant today over much
of the southern/central Plains and lower/mid MS Valley. A weak
mid-level perturbation is forecast to round the apex of the upper
ridge over the central CONUS and move east-southeastward across
parts of the Upper Midwest and Great Lakes through the day. A
separate and more amplified shortwave trough will dig
east-southeastward along the U.S./Canadian border through tonight.
At the surface, a convectively reinforced front should extend across
parts of the southern Great Lakes region into the central
Appalachians, with a very rich/moist low-level airmass present to
its southwest.

...Great Lakes/Ohio Valley into the Mid-Atlantic...
Mainly elevated thunderstorms will probably be ongoing at the start
of the period this morning across parts of Lower MI into OH. This
convection will be tied to modest low-level warm/moist advection and
related large-scale ascent. While an isolated threat for hail/gusty
winds may exist with this activity through the morning hours, it is
forecast to generally weaken through the day as the low-level warm
advection slowly weakens and capping becomes reestablished over the
warm sector. In the wake of these morning thunderstorms, most
guidance shows strong to locally extreme instability (MLCAPE
3000-5000+ J/kg) developing along/south of a weak front from
southern WI/northern IL into Lower MI and much of the OH Valley.
This very favorable thermodynamic environment will be aided by the
presence of mid 70s to perhaps low 80s surface dewpoints, steep
mid-level lapse rates emanating from an EML over the Plains, and
robust daytime heating.

Warm mid-level temperatures (700 mb around 10-14C) across the warm
sector will likely inhibit thunderstorm development for much of the
day. Still, modest ascent associated with a weak mid-level impulse
may be enough to breach the cap by late afternoon (around 21-22Z or
later) across parts of Lower MI and vicinity. Most 00Z
convection-allowing model guidance is in general agreement with this
plausible scenario. If thunderstorms can initiate, they would likely
become severe and pose an initial threat for both large hail and
damaging winds across Lower MI given around 30-40 kt of deep-layer
shear and very strong instability. Upscale growth into an intense
bowing cluster appears likely along/south of a warm front, and the
risk for severe/damaging winds would likely increase once an MCS
develops. Given the potential for extreme instability, some threat
for isolated 75+ mph winds may also exist across parts of southern
Lower MI into northern OH when the MCS matures. With ample
instability and some low-level shear present, a tornado or two also
appears possible with the cluster. The severe wind threat should
continue through the evening into parts of the OH Valley and central Appalachians before convection eventually weakens.

...Northern/Central Plains...
Ascent associated with a shortwave trough along the international
border, along with modest low-level convergence along a weak front,
should encourage convection to develop late this afternoon across
parts of ND. Weak to moderate instability and strong deep-layer
shear should support organized updrafts, with multicells and perhaps
a supercell or two possible. Isolated hail and severe wind gusts
should be the main threat with these thunderstorms as they move
eastward into parts of northwestern MN through this evening.
Confidence in greater coverage of severe convection across ND
remains too low to include higher severe hail/wind probabilities at
this time.

A somewhat separate area of convection should form this afternoon
from the Black Hills vicinity of SD into parts of western/northern
NE along/near a weak front. While deep-layer shear should be weaker
with southward extent across this area, it may still be sufficient
for loosely organized multicells, and perhaps a marginal supercell,
posing an isolated hail/wind threat through the early evening.

..Gleason/Weinman.. 08/24/2023

$$
--- SBBSecho 3.14-Linux
* Origin: Ilink: CCO - capitolcityonline.net (454:1/105)

ACUS01 KWNS 291239
SWODY1
SPC AC 291238

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0738 AM CDT Tue Aug 29 2023

Valid 291300Z - 301200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
FLORIDA...

...SUMMARY...
The potential for a few tornadoes will gradually increase near parts
of the Florida Gulf Coast into north Florida through tonight as
Hurricane Idalia approaches the Florida Big Bend.

...Florida...
Hurricane Idalia is forecast to further strengthen as it continues north-northeastward over the eastern Gulf of Mexico through tonight
-- reference the National Hurricane Center for the latest details.
In association with Idalia's northward movement, strengthening low
to mid-level flow will spread from south to north mainly across the
western half of the Florida Peninsula today. However, most guidance
indicate that hodographs will remain modest during the day but
increase in size during the evening and especially into the
overnight given the approach and expected strengthening of Idalia.
Model forecast soundings show poor lapse rates but very moist low
levels (mid 70s F dewpoints), yielding weak but supercell-sufficient
buoyancy. The risk for supercells and an isolated tornado threat
will be greatest late tonight through early Wednesday morning across
the west-central into northern Florida Peninsula.

...Northern Intermountain West/Northern Rockies...
Water-vapor imagery early this morning shows a potent upper trough
approaching the coastal Pacific Northwest, with this trough expected
to reach the northern Intermountain West and northern Rockies later
today and tonight. Diurnal heating and adequate moisture will yield
a weakly unstable airmass (250-1000 J/kg MLCAPE) across the region
with steep lapse rates. Scattered thunderstorms will likely develop
during the afternoon and spread northeastward and persist into the
evening. Isolated severe gusts and large hail will be possible with
the stronger storms, mainly across portions of northern/central
Idaho into western Montana.

...Appalachians vicinity and Mid-Atlantic States...
Scattered showers and thunderstorms are expected particularly this
afternoon through early/mid-evening. A moisture-rich airmass will
persist regionally, including some increase in moisture as a front
transitions across the Mid-Atlantic. Overall buoyancy will be fairly
limited by summertime standards with poor mid-level lapse rates and
thin CAPE profiles. Even so, a few stronger pulse-type storms
capable of gusty winds could occur mainly during the mid/late
afternoon hours through early evening, but the overall potential for severe-caliber storms is currently expected to remain low.

..Guyer/Goss.. 08/29/2023

$$
--- SBBSecho 3.14-Linux
* Origin: Ilink: CCO - capitolcityonline.net (454:1/105)

ACUS01 KWNS 291953
SWODY1
SPC AC 291951

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0251 PM CDT Tue Aug 29 2023

Valid 292000Z - 301200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PARTS OF
FLORIDA IN ASSOCIATION WITH HURRICANE IDALIA...AND CENTERED OVER THE BITTERROOTS...

...SUMMARY...
A few tornadoes will be possible late this afternoon through
tonight, mainly from the west central Florida Peninsula into the Big
Bend area, within the northeast quadrant of strengthening Hurricane
Idalia. Occasional damaging wind gusts will be possible across the
northern Rockies.

...20Z Update...
Little change was made to the existing severe probabilities at 20Z,
except for a minor eastward shift for a low wind threat into central
MT where minimal instability will develop due to steepening lapse
rates.

For the Southeast, the threat for a few tornadoes will increase
tonight, primarily after 03Z as stronger shear associated with
Hurricane Idalia overspreads parts of the western FL Peninsula, and
eventually into parts of the Big Bend.

..Jewell.. 08/29/2023

.PREV DISCUSSION... /ISSUED 1128 AM CDT Tue Aug 29 2023/

...FL Gulf coast through tonight...
Hurricane Idalia is strengthening as of midday over the southeast
Gulf of Mexico and is forecast to make landfall Wednesday morning
near the FL Big Bend as a major hurricane (please see latest NHC
advisories for additional information). Storm motion will be
largely parallel to the FL west coast into early tonight, so
eastward expansion of the stronger wind field and more favorable
low-level hodograph structures will be a gradual process (per the
trends in the VWPs from Key West and Tampa). Surface observations
show 77-80 F dewpoints across almost all of central/south FL, which
will help maintain surface-based buoyancy into this evening and
overnight. Thus, the primary increase in supercell/tornado threat
is expected late this afternoon into tonight from near Tampa
northward along the coast with the more cellular convection within
the outer eastern/northeastern bands.

...Northern Rockies this afternoon/evening...
A midlevel shortwave trough now over far northern CA and OR will
progress east-northeastward toward the northern Rockies by this
evening. Though low-level moisture is rather limited, strong
surface heating/deep mixing will result in inverted-V profiles with
weak buoyancy in advance of the midlevel trough and an associated
cold front. Thunderstorm development is expected this afternoon
through early tonight in the zone of ascent preceding the midlevel
trough (and along the front). The highest confidence in storm
development coincident with the steep low-level lapse rates and some enhancement to midlevel flow will be later this afternoon over the
Bitterroots, where a few damaging outflow gusts of 60-70 mph will be
possible.

$$
--- SBBSecho 3.14-Linux
* Origin: Ilink: CCO - capitolcityonline.net (454:1/105)

ACUS01 KWNS 300058
SWODY1
SPC AC 300057

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0757 PM CDT Tue Aug 29 2023

Valid 300100Z - 301200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR WESTERN
PORTIONS OF THE FLORIDA PENINSULA INTO THE BIG BEND OF FLORIDA...

...SUMMARY...
A few tornadoes will be possible tonight, mainly from the
west-central Florida Peninsula into the Big Bend area, within the
northeast quadrant of strengthening Hurricane Idalia.

...FL...
Hurricane Idalia will continue moving north-northeast tonight and be
located over the continental shelf waters near the Big Bend of FL by
early Wednesday morning. The wind fields in the northeast quadrant
will continue to intensify this evening initially near the Tampa Bay
vicinity, and later spreading into the northern portion of the
Peninsula. A few mini supercells are forecast to develop with an
attendant isolated risk for tornadoes. A few damaging gusts may
also accompany the more outflow-dominant bands/convective surges
with the more intense spiral bands. Have removed low-severe
probabilities over the Keys and the Everglades based on observed
wind fields (i.e., 00z Key West and Miami raobs and 88D VAD data)
being substantially weaker than farther north.

...Northern Rockies...
Water-vapor imagery early this evening shows a vigorous mid-level
shortwave trough over the Columbia Basin with this feature forecast
to move northeast through the northern Rockies tonight. Scattered thunderstorms over western MT into northern ID will continue to move
northeast through the evening. The 00z Great Falls, MT raob showed
dry adiabatic 0-4 km lapse rates and an inverted-v profile. The
threat for isolated severe gusts will be the hazard with the
stronger storms through mid-late evening before convective
overturning and instability wanes.

..Smith.. 08/30/2023

$$
--- SBBSecho 3.14-Linux
* Origin: Ilink: CCO - capitolcityonline.net (454:1/105)

ACUS01 KWNS 300546
SWODY1
SPC AC 300544

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1244 AM CDT Wed Aug 30 2023

Valid 301200Z - 311200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE NORTHERN
HALF OF THE FLORIDA PENINSULA INTO SOUTHEAST GEORGIA AND THE COASTAL
PLAIN OF THE CAROLINAS...

...SUMMARY...
A few tornadoes will be possible in association with Hurricane
Idalia through tonight from the northern portion of the Florida
Peninsula across southeast Georgia and into the eastern Carolinas.

...FL Peninsula/GA/Carolinas...
Hurricane Idalia and the associated strong to intense low-level wind
fields in the eastern semicircle will gradually shift
north-northeast during the day (see the latest National Hurricane
Center forecasts for the forecast track). Hodographs will initially
be enlarged and co-located with a very moist/tropical airmass near
and north of the I-4 corridor in the FL Peninsula and into perhaps
far southern GA during the morning. Several convective bands will
likely spread across the region with embedded cells. Some of the
stronger updrafts will potentially be capable of becoming
supercellular and could yield an isolated risk for a tornado with
the stronger/more persistent low-level mesocyclones. This corridor
of favorable shear/weak buoyancy overlap will gradually shift
north-northeast during the day and include the coastal plain of
GA/SC and eventually into eastern portions of NC tonight.

...Northeast...
A mid-level trough will quickly move from the Lower Great Lakes to
the New England coast during the day. Model guidance indicates a
band of showers/thunderstorms will probably be ongoing from eastern
NY northward into Maine and shifting east during the morning. Some
weak destabilization may occur in its wake during the afternoon, but
veered westerly low-level flow and decreasing moisture will become
less favorable for strong thunderstorm activity---precluding
low-severe probabilities this outlook.

...MT into ND...
A mid-level low/shortwave trough will move eastward across western
and central MT during the day. A few thunderstorms are possible by
early evening but weak instability will likely limit storm
intensity.

..Smith/Thornton.. 08/30/2023

$$
--- SBBSecho 3.14-Linux
* Origin: Ilink: CCO - capitolcityonline.net (454:1/105)

ACUS01 KWNS 021241
SWODY1
SPC AC 021239

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0739 AM CDT Sat Sep 02 2023

Valid 021300Z - 031200Z

...NO SEVERE THUNDERSTORM AREAS FORECAST...

...SUMMARY...
Organized severe thunderstorms are not expected.

...Synopsis/Discussion...
In mid/upper levels, the main belt of westerlies will remain largely
confined to Canada and the Great Lakes/Northeast this period --
well-removed from optimal low-level moisture still relegated to
portions of the Gulf Coast States and southward. South of those
westerlies, a split, blocky pattern will persist, with minor
adjustments from yesterday. Although a high aloft will remain over
the south-central Great Plains, a small, cut-off cyclone now
centered near SHV should meander west-northwestward toward the Red
River region north of DFW. General thunderstorms will remain
possible to its southeast, over much of the Gulf Coast region, amid
difluent flow, lift near residual low-level frontal zone across the
region, and rich low-level moisture.

Elsewhere, a prominent, cut-off, mid/upper-level cyclone is apparent
in moisture-channel imagery over much of OR, CA and NV, with a
center near Cape Mendocino. For most of the period, the cyclone
will meander near its present position, while weakening very
gradually. Near the end of the period, as a northern-stream
shortwave trough moves quickly southeastward down the BC Coast, the
cyclone will begin to open up and shift slightly eastward, heralding
its substantial deamplification and acceleration on day 2.

...Lower Colorado River Valley to Great Basin....
Widely scattered to scattered thunderstorms are expected through
this evening over a large area of the interior West, likely peaking
in coverage late this afternoon. This potential will be associated
largely with a broad plume of nearly southerly deep-layer flow east
of the cyclone, and associated moisture transport and warm
advection. Two areas of interest exist with conditional potential
for isolated severe gusts or hail, but not organized/focused enough
for an outlook area this cycle:

1. Lower Colorado and Imperial Valley regions, where the greatest
buoyancy will exist amid strong diabatic heating and rich low-level
moisture (upper 60s to mid 70s F lower-elevation surface dewpoints).
Those factors, along with a deep troposphere, will yield negligible
MLCINH beneath 2000-3000 J/kg MLCAPE and strongly difluent mid/
upper-level flow southeast of the coastal cyclone. However, deep-
layer flow will be weak, along with vertical shear, limiting
organization. Strong pulse downdrafts may occur from the most
intense multicell convection.

2. Central/northern NV, where afternoon heating, moisture and
instability will be more limited than farther south, but still
perhaps adequate for some surface-based convection. Some of the
resulting thunderstorms may exhibit at least transient supercellular characteristics in closer proximity to the eastern part of the
cyclonically enhanced flow field aloft, where 35-45 kt effective-
shear magnitudes and 500-800 J/kg MLCAPE are possible. Lack of
greater buoyancy for that shear suggests that any severe threat
remains too isolated and conditional for an outlook area.

..Edwards/Leitman.. 09/02/2023

$$
--- SBBSecho 3.14-Linux
* Origin: Ilink: CCO - capitolcityonline.net (454:1/105)

ACUS01 KWNS 031250
SWODY1
SPC AC 031248

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0748 AM CDT Sun Sep 03 2023

Valid 031300Z - 041200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PARTS OF
EASTERN NEVADA AND WESTERN UTAH...

...SUMMARY...
Isolated severe gusts and hail are possible across much of the
Intermountain West this afternoon and evening. Severe gusts may
concentrate over parts of eastern Nevada and western Utah.

...Synopsis...
The mid/upper-level pattern will become much more progressive over
the western CONUS, as an initially cut-off low near Cape Mendocino
devolves to a strong, open-wave trough and shifts inland. By 00Z,
the trough should extend from eastern OR southward across the
central/northern Sierra to coastal southern CA. By 12Z, it should
reach southwestern MT, southeastern ID, and the eastern border of
NV. The mid/upper trough should be preceded by a related low-level
cold front moving eastward across the Great Basin toward the
central/northern Rockies. The 00Z front should be located across
central MT, western WY, northwestern UT, and central NV. By the end
of the period, this front should extend from a low over western ND southwestward through the central Rockies to southern UT, with a lee
trough southward over the central High Plains.

As the mid/upper trough advances eastward, the longstanding high/
ridge over the south-central Plains will weaken. However, the
cut-off low now over north TX will remain too far from associated
height falls for any substantial influence until day 2, and in the
meantime, will meander erratically near its present position.
General thunderstorm potential will continue in an area of favorable
low-level moisture and difluent mid/upper winds from near the low to
its east and southeast, across the lower Mississippi Valley and
portions of the Gulf Coast States.

...Intermountain West...
Widely scattered to scattered thunderstorms are possible along/ahead
of the cold front this afternoon into evening, as an expansion/
extension of ongoing, initially nonsevere activity over northwestern
NV and southeastern OR. Isolated severe gusts and perhaps hail
could be observed almost anywhere over a vast area of the
Intermountain region and Great Basin. Within that, a relative
concentration of severe-gust potential in particular appears
possible across parts of northwestern UT and eastern NV.

A longstanding plume of moisture advection/transport from
subtropical latitudes, contributing for extensive convective
activity and precip the past few days over swaths of this area, will
persist and even expand today, under increasing influence from the
accelerating mid/upper trough. Large-scale lift -- both from warm
advection and DCVA -- will destabilize the mid/upper levels
somewhat, with already weak MLCINH essentially vanishing in areas
that can experience sustained diurnal heating. A midlevel dry slot
evident in satellite imagery may foster such destabilization over
parts of eastern NV/western UT, with resultant convection moving
northeastward over somewhat well-mixed boundary layers of lower
ground elevations. Modified model soundings suggest peak MLCAPE in
the 800-1300 J/kg range over the 15% wind area, amidst 35-45 kt
effective-shear magnitudes. As such, a blend of supercells and
multicells is possible, with some clustering of the latter further
contributing to local wind potential. Isolated large hail also will
be possible, mainly with any sustained supercells.

..Edwards/Leitman.. 09/03/2023

$$
--- SBBSecho 3.14-Linux
* Origin: Ilink: CCO - capitolcityonline.net (454:1/105)

ACUS01 KWNS 040539
SWODY1
SPC AC 040538

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1238 AM CDT Mon Sep 04 2023

Valid 041200Z - 051200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF
THE NORTHERN PLAINS...

...SUMMARY...
Thunderstorms capable of producing isolated to widely scattered
severe wind and hail will be possible Monday afternoon and evening
across parts of the northern Plains.

...Northern Plains...

Strong short-wave trough is currently located over the Great Basin,
progressing inland in line with latest model guidance. This feature
is forecast to advance into WY/western CO by late afternoon as
associated 500mb speed max ejects into the central Rockies and
gradually weakens. This evolution favors a lee surface low forming
over western SD by late afternoon. A synoptic front is expected to
be oriented northeast-southwest across the Dakotas into northern WY
by peak heating.

Boundary layer is expected to warm rapidly across the High Plains
from western NE into the Dakotas south of the aforementioned
synoptic wind shift. While readings will be somewhat cooler across
WY, convective temperatures will be breached by 20z, and scattered
convection should easily develop ahead of the short wave. HREF
guidance depicts a strong signal for high-based convection to
initiate over eastern WY then spread/develop northeast into a much
warmer air mass, with a deeper boundary layer characterized by
temp/dew point spreads around 40F. Forecast soundings exhibit ample
deep-layer flow and shear for organized updrafts. Current thinking
is a few supercells may be noted early in the period, but possibly transitioning into more clusters/bowing line segments downstream
over the Dakotas. Forecast buoyancy is not that strong, but there is
some concern for significant, organized gusts with these clusters,
especially given the steep lapse rates and large-scale support ahead
of the short wave. There may be a need for higher wind probabilities
across the northern Plains, but will maintain SLGT Risk at this
time. Convection, potentially organized, will spread northeast
across the Dakotas during the evening.

...AR/MO...

Weak upper low over north-central TX should open up and eject
towards the Ozarks later today. Seasonally cool mid-level
temperatures are noted with this feature, and modest 500mb flow will
spread across this region just ahead of the short wave. Forecast
soundings exhibit substantial buoyancy and multicell storms should
evolve as temperatures warm through the upper 80s to near 90F. Local
gusts and perhaps some hail could accompany this diurnally enhanced
convection.

..Darrow/Wendt.. 09/04/2023

$$
--- SBBSecho 3.14-Linux
* Origin: Ilink: CCO - capitolcityonline.net (454:1/105)

ACUS01 KWNS 050549
SWODY1
SPC AC 050548

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1248 AM CDT Tue Sep 05 2023

Valid 051200Z - 061200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE UPPER
MISSISSIPPI VALLEY...

...SUMMARY...
Isolated severe storms -- accompanied primarily by hail/wind
potential -- will be possible on Tuesday across parts of the Upper
Mississippi Valley. Gusty winds are also possible with isolated
storms across the mid Mississippi Valley into portions of the
southern Plains.

...Upper Mississippi Valley...

Strong short-wave trough is progressing east across the northern
High Plains early this morning. Latest water-vapor imagery depicts a well-defined mid-level vort near the Black Hills. This feature is
forecast to eject across SD early in the period before approaching
the SD/MN border around 05/00z. Associated surface front should sag
southeast across northwestern MN by mid day as a weak surface low
advances east across the upper MS Valley.

Latest radar data depicts a notable MCS has evolved over eastern ND
with a progressive-propagating squall line now spreading toward
northwest MN. This activity should spread into southeast
MB/northwest ON early in the period. By late morning, model guidance
suggests boundary-layer heating will aid destabilization immediately
ahead of the wind shift across northern/central MN. Renewed
convection should initiate along the wind shift by 18z then
spread/develop east toward the Arrowhead/northwestern WI. Forecast
soundings exhibit substantial flow/shear for supercells and initial
convection may be supercellular in nature. Thermodynamic profiles
favor hail and wind with this activity. Strong deep-layer flow and
adequate low-level shear suggest some tornado potential, but this
should be secondary to the hail/wind threat.

...Mid MS Valley/Southern Plains...

As the northern Plains short-wave trough advances toward the MS
Valley, stronger mid-level flow will spread across KS toward MO.
Some increase will likely be noted at lower latitudes into northern
OK/AR. There is increasing concern that isolated severe storms will
evolve along the southern influence of the short wave where intense
surface heating is expected ahead of the front. Latest model
guidance suggests a deep boundary layer along a corridor from
northwest TX, across central OK into southeast KS by late afternoon.
Forecast soundings suggest convective temperatures will be breached
between 22Z and 00Z as temperatures soar to near/just above 100F.
With seasonally high PW values, it appears gusty downbursts may be
noted with this activity. At this time will introduce a MRGL to
account for this threat, but some large-scale support appears
possible across southeast KS into MO as the ridge is suppressed.
This activity could be a bit more organized than convection farther
southwest along the wind shift across central OK into northwest TX.

..Darrow/Wendt.. 09/05/2023

$$
--- SBBSecho 3.14-Linux
* Origin: Ilink: CCO - capitolcityonline.net (454:1/105)

ACUS01 KWNS 060552
SWODY1
SPC AC 060551

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1251 AM CDT Wed Sep 06 2023

Valid 061200Z - 071200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE
ARK-LA-MISS VICINITY INTO NORTHERN MS...NORTHERN AL...AND MIDDLE
TN...

...SUMMARY...
Severe thunderstorms capable of damaging gusts and isolated hail are
possible from the Ark-La-Miss vicinity into northern Mississippi,
northern Alabama, and middle Tennessee.

...Synopsis...
Shortwave trough currently moving into the Upper MS Valley is
expected to continue gradually eastward throughout the day, ending
the period over the Lower MI. As associated surface low will take a
similar track eastward, while an attendant cold front pushes eastward/southeastward across the OH Valley and Mid MS Valley. A
moist air mass will precede this front, with scattered to numerous thunderstorms anticipated as the front moves eastward/southeastward.

Upper ridging will persist southwest of this shortwave trough,
centered over far west TX. To the northwest of this ridging, the
low-amplitude shortwave trough currently moving across central CA is
expected to progress northeastward through the western Great Basin
and into southern portions of the northern Rockies. Increasing
mid-level moisture and modest large-scale ascent attendant to this
shortwave will result in isolated to widely scattered thunderstorms
from the interior Pacific Northwest and northern Great Basin into
the northern Rockies.

...TN/Mid MS Valleys...
Isolated showers and thunderstorms will likely be ongoing early in
the period, supported by modest warm-air advection ahead of the
approaching shortwave trough and associated cold front. This early
activity should weaken, with strong heating and ample low-level
moisture resulting in airmass destabilization by the early
afternoon. Convergence along the front will be modest, but, given
the lack of convective inhibition, still sufficient for thunderstorm development. Moderate mid-level flow will accompany the approaching
shortwave, with some of this enhanced flow already over the region
when thunderstorms initiate. Strong buoyancy will support robust
updrafts, with the moderate shear contribute to some limited updraft organization and a low probability for severe hail. Storms will
likely then trend quickly towards largely outflow-dominant
structures after initial development, with water loading
contributing to strong downbursts. Shear will likely be strong
enough for some updraft/cold pool balance, with the development of
one or more forward-propagating convective lines probable. These
convective lines could take the threat for damaging gusts from the
Mid-South into more of middle TN and northern MS/AL during the
evening.

...Lower MI and Mid/Upper OH Valley...
Several rounds of showers and thunderstorms are anticipated across
the region today, starting later this morning amid broad warm-air
advection ahead of the front. Additional development, or perhaps re-intensification of any ongoing storms, is expected as a
pre-frontal trough moves across the region during the afternoon.
Another round is possible later in the early evening as the cold
front moves through, particularly if earlier storm coverage remains
isolated. Despite poor lapse rates, moderate buoyancy is still
expected across the region, supported by temperatures in the low 80s
and dewpoints in the low 70s. However, shear will be weak, and will
likely limit the overall severity of any thunderstorms. As such,
only isolated damaging gusts are currently anticipated.

..Mosier/Wendt.. 09/06/2023

$$
--- SBBSecho 3.14-Linux
* Origin: Ilink: CCO - capitolcityonline.net (454:1/105)

ACUS01 KWNS 200101
SWODY1
SPC AC 200059

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0759 PM CDT Tue Sep 19 2023

Valid 200100Z - 201200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
WEST AND NORTH TEXAS...INTO OKLAHOMA...

...SUMMARY...
Thunderstorms, associated with large hail (possibly greater than two
inches in diameter) and wind damage, will be likely from parts of
west and north Texas, into Oklahoma this evening.

...West and North Texas/Oklahoma...
Latest water vapor imagery shows evidence of a shortwave trough over
the central High Plains. RAP analysis has several vorticity maxima,
associated with the trough, located from western Oklahoma into
western Kansas. At the surface, a 1003 mb low is analyzed over
northwest Texas, with backed southeasterly flow over much of
Oklahoma and south-central Kansas. A pocket of maximized low-level
moisture is present in this area where surface dewpoints are
generally in the 60s F. This is contributing to a north-to-south
corridor of moderate instability, with the RAP estimating MLCAPE in
the 1500 to 2500 J/kg range. Thunderstorms are ongoing near the
instability axis from west-central Oklahoma south-southwestward into west-central Texas. Isolated storms are also located in
south-central Kansas. MCS development will be likely this evening as
the storms move east-southeastward across the southern Plains.

In addition to moderate instability, shear profiles across much of
the southern Plains appear favorable for severe storms. The 00Z
sounding from Norman, Oklahoma has 0-6 km shear near 45 knots with
strong directional shear from the surface to 700 mb. In addition,
700-500 mb lapse rates are near 8.5 C/km. This moderate deep-layer
shear, combined with steep mid-level lapse rates, will support
supercells with large hail this evening. Hailstones of greater than
two inches in diameter will be possible with the most intense
updrafts, mainly across southwest Oklahoma and northwest Texas. A
wind-damage threat will also be likely with supercells, and with
organized multicells. The severe threat is expected to continue
through much of the evening.

..Broyles.. 09/20/2023

$$
---
* SLMR 2.1a * "Excellent...excellent..." - Mr. Burns
* Origin: Ilink: CCO - capitolcityonline.net (454:1/105)

ACUS01 KWNS 271234
SWODY1
SPC AC 271233

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0733 AM CDT Wed Sep 27 2023

Valid 271300Z - 281200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS LATE THIS
AFTERNOON INTO TONIGHT ACROSS PARTS OF SOUTHERN ILLINOIS...SOUTHERN INDIANA...WESTERN AND NORTH CENTRAL KENTUCKY...

...SUMMARY...
Scattered strong thunderstorms may impact parts of the lower Ohio
Valley today into tonight, and pose some risk for severe weather.

...Synopsis...
A vigorous mid-level short wave trough progressing inland of the
Pacific Northwest coast is forecast to continue an
east-northeastward progression today through tonight, across the
northern U.S. Rockies into the Saskatchewan/Montana border vicinity
by 12Z Thursday. As this occurs, downstream blocking mid-level
ridging, initially centered along an axis south of Hudson Bay into
the St. Lawrence Valley vicinity, may undergo more notable
suppression by tonight, and a modest mid-level low to its southwest
may slowly accelerate eastward across southwestern portions of the
Great Lakes region.

In lower-levels, sprawling surface ridging, centered over Quebec,
will maintain considerable influence across the U.S., from the
Atlantic Seaboard into the Great Plains. However, broad weak
surface troughing will continue to be supported beneath the southern
periphery of the mid-level low, across the lower Missouri into Ohio
Valleys. Within this troughing, westward into the surface troughing
to the lee of the Front Range, one notable baroclinic zone will be
maintained. A weaker front likely will linger across northern
Florida and adjacent south Atlantic and Gulf coastal areas, with
high precipitable water content generally confined to areas along
and to its south, beneath broad troughing within a weak southern
branch of westerlies.

...Lower Ohio Valley vicinity...
Although generally south of the modest cold core (around or below
-14 C at 500 mb) of the slow moving mid-level low, it appears that
a gradual moistening of the boundary-layer may contribute to
destabilization with heating, along and south of the
quasi-stationary baroclinic zone. CAPE increasing to 1000-1500+
J/kg probably will initially be focused south through east of the
remnants of a cluster of storms now spreading across southern
Illinois into the lower Ohio Valley. While models suggest that this
convection will dissipate this morning, forcing for ascent
associated with a supporting mid-level jet streak (including 30-40
kt in the 700-500 mb layer) may contribute to renewed thunderstorm
development across the east central Kentucky Bluegrass into
Cumberland Plateau vicinity by mid afternoon. A couple of stronger
cells may be accompanied by small to marginally severe hail and
localized potentially damaging wind gusts, before the associated
forcing for ascent spreads into a more stable environment and/or
weakens.

In the wake of the initial perturbation, more substantive
boundary-layer destabilization (including CAPE increasing in excess
of 1000 J/kg) may commence along the baroclinic zone, east-southeast
of St. Louis through the Louisville vicinity from mid to late
afternoon into this evening. Preceding another mid-level jet streak propagating east-southeastward out of the lower Missouri Valley, and
perhaps coinciding with a zone of strengthening low-level warm
advection to the east of a developing weak frontal wave, it is
possible that the environment may become conducive to the evolution
of a few supercell structures and/or a small organized thunderstorm
cluster.

..Kerr/Bentley.. 09/27/2023

$$
--- SBBSecho 3.14-Linux
* Origin: Ilink: CCO - capitolcityonline.net (454:1/105)

ACUS01 KWNS 021228
SWODY1
SPC AC 021227

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0727 AM CDT Mon Oct 02 2023

Valid 021300Z - 031200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS EASTERN NEW
MEXICO AND ADJACENT WESTERN TEXAS...

...SUMMARY...
Thunderstorms, associated with large hail and wind damage, will be
possible this afternoon and evening across parts of the southern
Rockies and southern High Plains. Marginally severe storms will be
possible in parts of the central Rockies, and in parts of the
central and northern Plains.

...Synopsis...

An amplified upper trough over the Intermountain West will shift
east today/tonight toward the Rockies/High Plains. An associated
belt of enhanced deep-layer south/southwesterly flow will overspread
the Rockies and adjacent High Plains. Deep-layer flow will be rather
meridional through the central/northern High Plains, with somewhat
more southwesterly flow focused over the southern High Plains
vicinity.

At the surface, lee troughing will extend along much of the High
Plains. Some stronger surface cyclogenesis is forecast from the
WY/SD/NE vicinity into the central Dakotas during the latter half of
the forecast period. Southerly low-level flow will result in modest boundary-layer moisture (50s to low 60s F) near/to the east of the
surface trough axis. With northward extent into the Dakotas, capping
in the 850-700 mb layer will largely preclude surface-based
convection. Further south, deep boundary-layer mixing and somewhat
better low-level moisture will allow for more surface-based
convection. Isolated to scattered strong/severe thunderstorms are
expected this afternoon into tonight across from the southern High
Plains vicinity into parts of the Dakotas. The main hazards with
this activity will be large hail and strong/severe gusts.

...Southern Rockies/High Plains vicinity...

Focused severe potential will be aided by higher quality
boundary-layer moisture (supporting moderate instability), and
vertically veering wind profiles, indicating supercell potential. A
few rounds of thunderstorms are possible in a persistent low-level
upslope flow regime, with severe potential increasing by
mid-afternoon and persisting into evening. Forecast hodograph show
modest low-level curvature due to relatively weak low-level flow
through 1-2 km. However, hodographs becoming elongated/straight
above this layer. Favorable thermodynamics and shear should support
large hail potential, while steep low-level lapse rates suggest
strong outflow gusts will be possible.

...Central High Plains into the Dakotas...

A low will deepen over far southeast WY today, while southerly
low-level flow ahead of the low maintains 50s F surface dewpoints.
Stronger heating focused across northeast CO/far southeast WY into
western NE will aid in a corridor of moderate instability. With
northward extent into the Dakotas, capping will limit surface-based instability. Initial thunderstorm development is expected by late
afternoon near the surface low vicinity. Isolated hail and strong
gusts will be possible with this activity. An organized thunderstorm
cluster will likely shift north/northeast during the evening/early
overnight period across parts of western SD into western/central ND.
This activity will be elevated above a capping inversion and mainly
pose a risk for sporadic hail.

..Leitman/Thompson.. 10/02/2023

$$
--- SBBSecho 3.14-Linux
* Origin: Ilink: CCO - capitolcityonline.net (454:1/105)

ACUS01 KWNS 111253
SWODY1
SPC AC 111251

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0751 AM CDT Wed Oct 11 2023

Valid 111300Z - 121200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PARTS OF CENTRAL/NORTHERN FLORIDA TO THE COASTAL-BEND REGION...

...SUMMARY...
Damaging thunderstorm gusts and a few tornadoes are possible this
evening and tonight over parts of central/northern Florida to the
coastal-bend region.

...Synopsis...
The mid/upper-level pattern features a couple synoptic-scale
cyclones -- one centered over northeastern ON south of James Bay,
the other near the western coastline of the Olympic Peninsula --
forming the feet of an apparent omega block with the anticyclone
over north-central Canada. However, unlike many omega patterns on
the timescale of a day, this one will be decidedly progressive, with
the eastern cyclone continuing to fill and shift eastward back into
QC. Meanwhile, the western cyclone -- currently accompanied by a
negatively tilted trough extending southeastward over NV -- will
weaken inland over WA/southern BC, while another forms along the
trough tonight, over the south-central WY/northwestern CO vicinity.
Height falls and strongly difluent, cyclonic flow aloft will spread east-southeastward across the central/southern Rockies and then the
adjoining Great Plains by 12Z tomorrow.

The intervening synoptic ridge -- now evident over the central/
northern Plains -- will shift eastward to MO/IA/MN around 12Z. By
that time, the western cyclone, and the quasistationary mid/upper
high over northern Canada, will form more of a Rex configuration.
To its southeast, the mid/upper-level portions of former Pacific
Hurricane Lidia (the low levels having been shredded in the lofty/
rugged terrain of central MX) are moving northeastward from central
to northeastern MX. Associated vorticity banners aloft will cross
deep south TX, the northwestern Gulf, and the central Gulf Coast.
Though not very intense, enough low-level mass response is expected
to aid frontal-wave cyclogenesis over the Gulf through the period.

The surface warm front was analyzed at 11Z across south FL, bending northwestward over the northeastern Gulf south of AAF, then west-
southwestward to a 100-mb frontal-wave low over the northwestern
Gulf, roughly east of BRO and south of BPT. The low should ripple northeastward along the northward-moving segment of the boundary to
near the mouth of the Mississippi River by 00Z, then weakening and
moving eastward across northern FL by 12Z, with additional
development possible on the frontal segment over the nearby
Atlantic. Meanwhile, cyclogenesis will occur over eastern CO by
00Z, as the mid/upper trough approaches, with warm front eastward
across northern MO and cold front southwestward across the Four
Corners area. By 12Z, a well-developed low should be located near
MCK, with cold front southwestward near an EHA-TCS line and warm
front over east-central NE, southern IA and central IL.

...Central/northern FL to coastal-bend region...
Areas of scattered to numerous thunderstorms should shift east-
northeastward across the north-central/northeastern Gulf throughout
the day and into tonight, and begin to impinge on coastal west- central/northwestern FL this evening and overnight. Additional
activity may develop ahead of the Gulf convection, in a weakly
capped and favorably moist inland boundary layer near the
northward-moving front. A few tornadoes and damaging gusts appear
to be the main threats. Density of convection, and related
outflows, make severe potential more conditional with northward
extent over the northern FL/eastern Panhandle area.

Hodographs should enlarge throughout the afternoon and especially
tonight over the outlook area, as the frontal-wave low approaches,
low-level windspeeds above the surface increase in the associated
mass response, and the front itself shifts northward with backed
flow in the associated baroclinic zone. Modest nocturnal low-level
lapse rates should limit buoyancy, with MLCAPE near and south of the
front generally in the 500-1000 J/kg range inland (locally higher).
Though modest for the geographic area, this can support surface-
based supercells, given the presence of effective SRH commonly in
the 150-250 J/kg range and locally larger.

Some offsetting factors preclude a greater unconditional tornado
risk at this time. An increase in forecast buoyancy near the
western coastline, the last few hours of the period, coincides with
veering of near-surface winds that also will reduce hodograph size/
SRH. Potentially dense/messy convective character and lack of
larger near-surface instability also are factors. Still, at least a
few potentially tornadic supercells appear possible within the
broader mass of thunderstorms. With a preponderance of guidance
reasonably indicating the eastward expansion of both a favorable
supercellular parameter space and surface-based convective potential
toward the Atlantic Coast before 12Z, the outlook area has been
extended accordingly.

...Central Plains/Corn Belt...
Ongoing/nonsevere convection over parts of western IL to northern MO
and southern IA should remain so through the rest of the morning as
the supportive low-level flow and isentropic lift weaken. A rogue
hail core near severe levels cannot be ruled out, but appears
improbable at this time, based on convective and environmental
trends.

The same elevated, low-level regime of warm advection and moisture
transport contributing to that activity should shift/redevelop
northwestward through today, then intensify considerably from late
afternoon into tonight, amid the mass response to the approaching
mid/upper trough. Increased transposition of cooling aloft and
low-level theta-e advection will steepen lapse rates and increase
buoyancy, while gradient flow aloft and deep shear also strengthen.
The net result should be a band or two of scattered thunderstorms
this evening and overnight, with episodic, marginally severe hail.
Activity (especially in western areas of the outlook, over NE/SD)
will be supported by a 30-50-kt LLJ east of the intensifying
low-level cyclone, with around 1000-2500 J/kg MUCAPE and 30-40-kt effective-shear magnitudes. Though 850-mb flow is progged to be
more difluent with eastward extent into IA/IL, sufficient speed
convergence should exist to support lift of parcels to LFC and
marginal hail potential there as well. While not likely, a marginal
threat for a severe gust is indicated over parts of NE as well, by
the presence of a somewhat dry, inverted-v character to much of the
boundary layer depth underlying the elevated convective inflow
region in forecast soundings.

..Edwards/Broyles.. 10/11/2023

$$
--- SBBSecho 3.14-Linux
* Origin: Ilink: CCO - capitolcityonline.net (454:1/105)

ACUS01 KWNS 121251
SWODY1
SPC AC 121250

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0750 AM CDT Thu Oct 12 2023

Valid 121300Z - 131200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF NORTHERN/CENTRAL FLORIDA. AND OVER PARTS OF THE CENTRAL PLAINS...

...SUMMARY...
Large hail, damaging gusts, and a tornado or two are possible today
over parts of the central Plains. A few tornadoes and damaging
gusts still may occur through midday over portions of
northern/central Florida.

...Synopsis...
The mid/upper-level pattern is dominated by a temporary Rex
configuration over central/western North America, with a
quasistationary anticyclone over north-central Canada, and a
pronounced, synoptic-scale cyclone over the central/northern Rockies
and eastern Great Basin. An omega pattern will redevelop by late in
the period, as the western cyclone shifts eastward across the
central Plains, while weakening somewhat. The associated 500-mb low
should be near EAR by 00Z, moving slower overnight to a position
over eastern NE. By that time, the accompanying trough should be
positively tilted, extending southwestward to the TX Panhandle, with
most (if not all) midlevel DCVA behind the surface cold front
described below. For this outlook, surface synopses will appear in
their geographic sections.

...FL...
A few tornadoes and severe gusts remain possible across the outlook
area today. For near-term guidance, see tornado watch 708 and
related mesoscale discussions.

A slow-moving warm front was drawn across north-central FL,
extending westward into a weak frontal-wave low over the eastern FL Panhandle/coastal-bend region. The FL surface low initially analyzed
near AAF may move only slightly eastward through the day, while the
cold front to its south pivots eastward over the northeastern Gulf.
The frontal zone to its east should become quasistationary over
northernmost portions of FL today, with additional low development
possible over Atlantic waters east of JAX. Then from mid/late
afternoon onward, the frontal zone should sag southeastward over
northern FL, aided by persistent/antecedent precip to its north and
isallobaric effects related to the Atlantic cyclogenesis.

As these processes occur, near-surface flow should continue to veer
gradually with time, slowly reducing both hodograph size, low-level
lift, and SRH. However, through the remainder of the morning into
early afternoon, this will be concurrent with improved instability
south of ongoing clouds/precip. Surface heating of a richly moist
airmass south of the warm front, with 70s F surface dewpoints
offsetting modest midlevel lapse rates, should yield 2000-3000 J/kg
peak MLCAPE. As such, supercell/tornado threat is expected to
linger into midday with only a slow decrease in potential as shear
diminishes. The damaging-wind threat will last the remainder of the
day and into early evening, and perhaps slightly farther south, on
at least isolated basis.

...Central Plains...
Scattered strong-severe thunderstorms, including supercells, are
most likely this afternoon into early evening over central/eastern
NE, building southward/eastward with time into parts of northern/
eastern KS, and persisting tonight into western IA and northwestern
MO before weakening. Large hail, severe gusts and a few tornadoes
will be possible.

At 11Z, surface analysis showed a low near MCK, with cold front
across western KS to north-central NM, and warm front over southern
NE, northern MO and south-central IL. A dryline was drawn over the
western TX Panhandle to the Llano Estacado near the TX/NM border,
southward into the Big Bend region. This boundary should mix/advect
eastward today to western OK, northwestern TX, and the lowest art of
the Pecos Valley. Overnight, the cold front will overtake the
dryline from north-south. By 00Z, the Plains low should move slowly
to central NS and become very nearly stacked with the mid/upper-
level vortex center, with which it should maintain vertical
continuity through the rest of the period. The 00Z cold front
should arc across central KS, northwestern OK, the TX South Plains,
and southeastern NM, with warm front across southern IA and central
IL. By 12Z, the cold front should extend across eastern KS,
south-central OK and southwest TX, with warm front over
north-central IL and central IA.

A band or arc of thunderstorms, of mixed linear/supercellular
character, is expected to develop by midday over NE, near the
surface low and adjoining cold-frontal segment, where deep-layer
forcing will be maximized. So will assorted measures of vertical
shear (deep/effective shear, hodograph size, and vector shear in the
boundary layer), especially near the warm front -- but still
favorable southward into the warm sector. Forecast soundings
suggest 200-400 J/kg effective SRH over much of central/eastern NE
and northern KS, locally higher where parcels are still surface-
based in the warm-frontal zone, and diminishing southward into
southern KS. The eastern rim of the strongest cooling aloft,
spreading atop a narrow segment of the warm sector and associated
low 60s F surface dewpoints, should combine with limited diurnal
heating to support a narrow pre-cold-frontal corridor of 500-1500
J/kg MLCAPE this afternoon.

Convective/severe potential southward into OK is more isolated and
conditional, given weak to neutral large-scale support, less low-
level mass response to the cyclone aloft than farther north, and
smaller midlevel lapse rates with southward extent. Still, several
models extend enough frontal forcing into north-central/northeastern
OK to support at least isolated sustained convection, in an
environment that will be at least marginally supercell/severe-
favoring. As such, the MRGL area has been extended southward for
this cycle.

..Edwards/Broyles.. 10/12/2023

$$
--- SBBSecho 3.14-Linux
* Origin: Ilink: CCO - capitolcityonline.net (454:1/105)

ACUS01 KWNS 141248
SWODY1
SPC AC 141246

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0746 AM CDT Sat Oct 14 2023

Valid 141300Z - 151200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF
EASTERN NORTH CAROLINA...

...SUMMARY...
Potential exists for damaging to marginally severe gusts and/or a
tornado today over portions of eastern North Carolina.

...Synopsis...
Over the CONUS, amplification of the mean mid/upper-level pattern is
expected through the period, as a ridge builds over the West, and a
series of shortwave troughs contributes to net height falls and
cyclonic flow over a broad area from the Gulf Coast to the Great
Lakes and Atlantic Seaboard. The two strongest of those shortwave
troughs are apparent in moisture-channel imagery over:
1. Portions of WI/IL/MO, with a weak 500-mb low over northern IL.
This feature will continue to devolve to an open-wave trough and
lose amplitude, crossing the upper Ohio Valley and central
Appalachians early this evening, then the Mid-Atlantic Coast around
06-9Z.
2. Western SD initially, with an at least intermittently closed
500-mb low moving southeastward to east-central NE by 00Z, then
southwestern MO around 12Z tomorrow.

Approach of the leading mid/upper perturbation will strengthen an
initially weak, frontal-wave surface low, analyzed at 11Z over
eastern SC between SSC-CHS at 11Z. A cold front was analyzed from
that low south-southeastward across Atlantic waters then bending
southwestward over south-central FL to the central Gulf. An
occluded front extended from the SC low into a broad area of low
pressure over OH/IN/IL, under and ahead of the midlevel circulation
center. A warm front was drawn from the SC low northeastward along
or just south of the southern coast of NC and past HSE. A shallow
stable layer in the 12Z MHX RAOB, with light southeast winds,
indicated the boundary was just south of there, near the immediate
beaches. The warm front should spread inland through the afternoon,
but probably in a diffuse and erratic manner because of precip to
its north. By 00Z the coastal low and warm front should move
northeastward to near Cape Charles/southernmost Delmarva region,
with cold front southward over easternmost NC. This low and the
warm front should shift offshore thereafter.

...Eastern NC...
Ongoing precip is apparent in irregularly sized patches over the
eastern Carolinas, especially NC. Little or no thunder has occurred
in the last few hours, likely related to a layer of poor midlevel
lapse rates well-sampled by the 12Z CHS sounding. This activity,
and associated areas of clouds/precip, will substantially limit
diabatic heating for much of the day across the outlook area.
However, the low-level airmass in the cloud/precip area, while
characterized by stable to neutral lapse rates initially, only needs
weak heating and warm/moist advection to yield enough theta-e for
surface-based effective-inflow parcels to overcome the weak midlevel
lapse rates. That should occur, with upper 60s to low 70s F surface
dewpoints spreading northward/inland over eastern NC east through
southeast of the low. 500-1000 J/kg MLCAPE is possible in a narrow
plume ahead of the cold front, which also may support a conditional
second round of convection along the front, in a broken arc.
Effective-shear magnitudes of 45-55 kt suggest some of the
convection may become supercellular -- especially whatever can
remain discrete through maturity.

In both cases (leading plume and possible frontal follow-up),
forecast soundings suggest hodographs will be well-curved but not
particularly large, leading to marginal SRH with values such as:
effective and 0-3 km of 100-300 J/kg, and 0-1-km of 75-150 J/kg.
Vorticity enhancement along favorably positioned outflow/
differential-heating boundaries may contribute to some local maxima
in storm-scale rotation and tornado potential, but this threat
appears quite conditional and isolated. The most intense cells also
may produce damaging winds, and a severe gust cannot be ruled out.

..Edwards/Broyles.. 10/14/2023

$$
--- SBBSecho 3.14-Linux
* Origin: Ilink: CCO - capitolcityonline.net (454:1/105)