Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sat Aug 05 2023 04:46:42 AWUS01 KWNH 050446 FFGMPD ILZ000-MOZ000-IAZ000-051000- Mesoscale Precipitation Discussion 0867 NWS Weather Prediction Center College Park MD 1246 AM EDT Sat Aug 05 2023 Areas affected...Western Illinois Concerning...Heavy rainfall...Flash flooding likely Valid 050444Z - 051000Z SUMMARY...Swath of heavy rain and flash flooding to continue drifting east from northern Missouri into western Illinois into the overnight. Rainfall rates of 2 to 3 inches per hour should overcome the progressively drier antecedent conditions to the east into Illinois, so flash flooding is considered likely. DISCUSSION...Regional NEXRAD denotes a well defined swath of heavy rain ahead of an MCV/Shortwave and north of a surface low across northeastern MO which is slowly drifting east. Maintenance of this convergent swath is expected into western IL as southeasterly low level inflow brings some drier and unstable air from southern IL on top of high moisture under this MCV and south through eastern MO with PW of 2 to 2.2". The deeper moisture intersection near the surface low and northward should continue to have ample narrow skinny CAPE for strong updrafts and moisture flux for 2-3"/hr rates into or through the rest of the overnight. Slow, nearly due eastward progression of the MCV/surface wave should keep orientation of some cells to align favorably for longer duration and support a swath of highest rainfall totals of 3 to 5" with locally 6" possible. Western IL has generally missed all the heavy rain that central and eastern MO has received over the past several days, so FFG greatly increases east into IL to generally around 3"/3hr. However, given the slow motion and highly efficient rainfall of longer than an hour duration, flash flooding is considered likely through 10Z. Jackson ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!8yrI2HWSUdlMQF23HYF4W9dvhc410oDnhV7y8rGQ3plYS-mudxBcz3jpjPPpLj7opvfU= 7AZkbYFAlT5yDiv2mxu_9sw$ for graphic product... ATTN...WFO...DVN...ILX...LSX... ATTN...RFC...NCRFC...NWC... LAT...LON 40689115 40679006 40418947 39888943 39438987=20 39299060 39599128 39879216 40409233 40539177=20 =20=20=20=20=20=20=20=20=20=20=20=20 =3D =3D =3D To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM. --- SBBSecho 3.14-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .