AWUS01 KWNH 181536
FFGMPD
ILZ000-MOZ000-KSZ000-182134-

Mesoscale Precipitation Discussion 0183
NWS Weather Prediction Center College Park MD
1135 AM EDT Mon May 18 2026

Areas affected...southern/central Missouri through southern
Illinois

Concerning...Heavy rainfall...Flash flooding possible

Valid 181534Z - 182134Z

Summary...Heavy rainfall will likely continue through 21Z along
and north of the I-44 corridor, with areas of flash flooding
possible.

Discussion...A mature, elongated MCS continues to provide areas of
training thunderstorms along an axis from near Fort Scott,
KS/Nevada, MO east-northeastward through Saint Louis Metro and
into south-central Illinois.  The MCS has become a bit more
perpendicular to southwesterly low-level flow (around 40-45 kts at
850mb), supporting repeating/training convection.  The elevated
nature of the convection suggests seems to have limited rainfall
rates to only around 1 inch/hr in a few spots. However, the
persistence of convection (likely supported by an approaching
shortwave from the Arkansas Ozarks) should likely continue
reinforcing the mature cold pool and resulting in several more
hours of occasionally heavy rainfall.

While rain rates may not breach 1-hr FFG thresholds on a
widespread basis, it appears possible that 2.5 inch/3-hr rates
could be achieved at times along this axis.  This should result in
at least isolated flash flood potential - particularly in any
low-lying and urban parts of the discussion area.  Again, the
rainfall/flash flood potential will likely continue through at
least 21Z/4p CDT.

Cook

...Please see www.wpc.ncep.noaa.gov for graphic product...

ATTN...WFO...EAX...ILX...LSX...PAH...SGF...

ATTN...RFC...KRF...MSR...ORN...TIR...TUA...NWC...

LAT...LON   40018956 39938838 39348784 38518808 37868904 
            37189093 37139355 37549452 38229469 38749458 
            39069390 39649156