Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Wed Sep 24 2025 20:25:54 AWUS01 KWNH 242025 FFGMPD TNZ000-KYZ000-INZ000-ILZ000-MOZ000-ARZ000-250130- Mesoscale Precipitation Discussion 1132 NWS Weather Prediction Center College Park MD 425 PM EDT Wed Sep 24 2025 Areas affected...lower to mid-MS Valley into northwestern TN and KY Concerning...Heavy rainfall...Flash flooding possible Valid 242023Z - 250130Z Summary...At least an isolated flash flood threat will evolve through this evening from the lower/middle MS Valley into northwestern TN and KY. Hourly rainfall of 1 to 2 inches and localized totals of 2 to 4 inches are expected through 01Z. Discussion...Radar trends over the past hour have shown an increase in the coverage of showers and thunderstorms from northeastern AR into southeastern MO and western KY. These storms were forming along a quasi-stationary front and just ahead of a positively tilted mid to upper-level trough axis located over IL/MO into northeastern OK as observed on water vapor imagery. Filtered sunshine and anomalous PWAT values of 1.5 to 2.0 inches have contributed to MLCAPE of 500 to 1000+ J/kg via 20Z SPC mesoanalysis data. 850 mb winds of 20 to 30 kt were observed across the lower MS Valley into northern MS/southwestern TN via VAD wind data, just ahead of the base of the mid-level trough. As the trough axis advances eastward through the evening, the region of locally stronger low level winds are forecast by the RAP to expand northeastward into TN/KY, aiding with axes of low level convergence (in addition to the surface front and resultant outflows). This will occur beneath a divergent pattern aloft within the right-entrance region of a 110-130 kt jet at 250 mb expanding northeastward from MO/IL. The result should be an increase in thunderstorm coverage, especially over the lower/middle MS Valley with areas of training from SW to NE. Within axes of training, hourly rainfall of 1-2 inches will be likely with potential areas of flash flooding from 2 to 4 inches of storm total rainfall through 01Z to 02Z. Given somewhat meager instability and low level winds into KY/TN, the response is not expected to be well organized or widespread with any instances of flash flooding most likely remaining isolated to widely scattered. Otto ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!9P6K1YSV1g-oYcsPKuRKvFlzLvYcIb1lOcX1ZD2dHC2KZTFTB8T6nspZU7uxLQV6Q9Ts= fKocw4fFrIkTggaDdrCiav0$ for graphic product... ATTN...WFO...JKL...LMK...LZK...MEG...OHX...PAH...SGF... ATTN...RFC...MSR...ORN...TIR...NWC... LAT...LON 38178393 37948310 37498279 37148314 36848430=20 36318687 35898854 35299000 35149152 35749202=20 36899120 37788852 38108581=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 3.28-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .