Mesoscale Discussion 1620
NWS Storm Prediction Center Norman OK
0429 PM CDT Tue Jul 18 2023
Areas affected...far western Tennessee...northeast Arkanas...and
northern Mississippi
Concerning...Severe potential...Watch likely
Valid 182129Z - 190000Z
Probability of Watch Issuance...80 percent
SUMMARY...At least isolated damaging gusts or marginal hail will
remain possible for a few more hours, and a new watch is likely.
DISCUSSION...Radar shows a decelerating outflow boundary extending
from extreme northeast AR to just northeast of the Memphis TN area.
Recent trends indicate strengthening storms on the southern
fringe/outflow of the southeast MO MCS, with impressive echo IR
presentation. Surface analysis confirms a very moist and unstable
air mass remains in place south of the AR activity and west of the
TN outflow, with dewpoints approaching 80 F in spots. Given the
uncapped air mass and robust convection now ongoing over northeast
AR, a new watch will likely be issued downstream extending into
parts of western TN and northern MS.