Mesoscale Discussion 1961
NWS Storm Prediction Center Norman OK
0516 AM CDT Sat Aug 12 2023
Areas affected…Southeast MO into southern IL
Concerning…Severe Thunderstorm Watch 632…
Valid 121016Z – 121145Z
The severe weather threat for Severe Thunderstorm Watch 632
SUMMARY…A damaging-wind threat will continue to spread
southeastward this morning. WW 632 has been locally expanded
downstream of ongoing storms.
DISCUSSION…A bowing storm cluster is currently moving through the
St. Louis area as of 1015 UTC. This cluster strengthened northwest
of St. Louis, and became rather intense with 60-80 kt radar
velocities noted within 1 km AGL, but preceding outflow and
near-surface stabilization appear to have somewhat limited the
potential for these intense velocities to reach the surface.
However, given the current intensity and organization of this
cluster, wind damage and localized severe gusts will continue to be
a threat in the short term as convection spreads southeastward.
Some damaging-wind potential will likely spread south of the initial
bounds of WW 632, and the watch has been locally expanded as a
result. Evolution of the severe threat later this morning remains
somewhat uncertain, though some decrease in storm organization and
attendant damaging-wind potential is possible if outflow continues
to surge well ahead of the strongest convection.
…Please see www.spc.noaa.gov for graphic product…
LAT…LON 38549135 38718977 38918869 38728775 38228794 37668823
37618869 37528962 37529025 37739086 37869106 38029116