ZCZC SPCSWOMCD ALL
ACUS11 KWNS 182312 
SPC MCD 182312 
INZ000-KYZ000-ILZ000-MOZ000-190045-

Mesoscale Discussion 0488
NWS Storm Prediction Center Norman OK
0612 PM CDT Thu Apr 18 2024

Areas affected...Southeast MO into southern IL...extreme southwest
IN...and western KY

Concerning...Severe Thunderstorm Watch 125...

Valid 182312Z - 190045Z

The severe weather threat for Severe Thunderstorm Watch 125
continues.

SUMMARY...The threat for severe hail and wind, along with an
embedded tornado or two, will spread quickly eastward this evening.
Eventual downstream watch issuance is likely.

DISCUSSION...A broken line of thunderstorms moving across
east-central/southeast MO into southwest IL has shown signs of
accelerating eastward early this evening, as new cells have merged
into the line near/north of the St. Louis area. Increasing outbound
velocities have been noted from the KLSX radar, and damaging wind
gusts of 60-75 mph may become an increasing threat through the
evening as the line of storms moves quickly eastward into a region
where modestly strong heating occurred this afternoon. Meanwhile,
moderate instability will continue to support a hail threat with any
embedded supercells. A modest increase in low-level flow/shear is
expected ahead of the line this evening into south-central/southeast
IL and southwest IN, which will support a threat of an tornado or
two, both with any embedded supercells, and also with stronger QLCS
mesovortices. 

The line of storms will likely approach the edge of WW 125 between
00-01Z, with downstream watch issuance likely into parts of
southeast IL and southwest IN.

..Dean/Guyer.. 04/18/2024

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...LMK...IND...PAH...ILX...LSX...SGF...

LAT...LON   37419215 37559213 39158977 40178876 40108698 38448689
            37538711 37338950 37308993 37289030 37249102 37229177
            37419215 

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