Mesoscale Discussion 1962
NWS Storm Prediction Center Norman OK
0753 AM CDT Sat Aug 12 2023
Areas affected...Parts of the OH Valley
Concerning...Severe potential...Watch unlikely
Valid 121253Z - 121430Z
Probability of Watch Issuance...20 percent
SUMMARY...Some threat for isolated hail and damaging gusts will
persist into mid morning. Some portions of the region may see a
greater severe risk later today.
DISCUSSION...At 1245 UTC, a broad arc of convection is ongoing from central/southern IN into far southern IL and southeast MO. The
southwestern storms are associated with a remnant MCS and related
outflow that earlier produced wind damage near St. Louis. Moderate
downstream buoyancy may support an isolated damaging-wind threat as
storms move into western KY/TN, though widespread cloudiness will
tend to delay stronger destabilization and steepening of low-level
lapse rates.
Storms across central/southern IN within a low-level warm advection
regime are somewhat more intense and less influenced by outflow. Mid/upper-level flow and deep-layer shear is also somewhat stronger
across IN/OH compared to areas farther southwest, and a marginal
elevated supercell or two will be possible with a threat of isolated
large hail and locally damaging gusts through mid morning.
Near-term watch issuance is considered unlikely, due to the isolated
nature of the ongoing threats. Depending on trends regarding diurnal destabilization and potential transition from elevated to
surface-based convection, portions of this region may see a greater
severe threat later today.