MD 0788 CONCERNING SEVERE THUNDERSTORM WATCH 222… FOR FAR EASTERN MISSOURI INTO CENTRAL AND SOUTHWEST ILLINOIS
Mesoscale Discussion 0788
NWS Storm Prediction Center Norman OK
0238 PM CDT Sat May 13 2023
Areas affected...Far eastern Missouri into central and southwest
Illinois
Concerning...Severe Thunderstorm Watch 222...
Valid 131938Z - 132145Z
The severe weather threat for Severe Thunderstorm Watch 222
continues.
SUMMARY...The threat for severe winds and large hail continues
across WW 222. The severe threat will likely be focused across
central and southwest Illinois over the next 2 hours.
DISCUSSION...KLSX radar imagery shows two semi-organized
clusters/lines of storms moving into central IL and over the St.
Louis area. The northern of these two clusters has recently shown
signs of intensification in GOES IR imagery and lightning data, as
well as in velocity data that depicts early signs of cold pool
consolidation/organization. A surface thermal maximum is noted
downstream in recent surface obs where temperatures on the low/mid
80s and SBCAPE should be regionally maximized. These trends suggests
that damaging winds may become the predominant threat over the next
couple of hours as line approaches central IL.
To the south, a cluster of storms has had a history of severe hail
with hail stones as large as 2 inches reported per recent LSRs.
Similar to the line of storms to the north, IR imagery depicts
periods of rapid cloud top cooling indicative of intense updrafts.
Additional convection developing along the outflow from the original
storms to the south of the St. Louis area will likely lead to
further clustering/upscale growth over the next hour as storms
migrate into southwest IL. While the severe hail threat will
continue in the near term, the damaging wind potential may increase
downstream as gradual upscale growth continues over the next 2-3
hours. A local expansion on the southern end of WW 222 may be needed
in this time frame.
..Moore.. 05/13/2023
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...PAH...ILX...LSX...
LAT...LON 38719079 39029059 39329055 39659060 39789062 39979048
40139003 40168981 40138926 40038890 39768855 39428846
39138843 38798862 38638873 38218901 38028917 37918938
37888974 38129068 38229081 38419086 38719079
