Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Fri Jul 11 2025 18:29:37 AWUS01 KWNH 111829 FFGMPD MSZ000-112228- Mesoscale Precipitation Discussion 0645 NWS Weather Prediction Center College Park MD 229 PM EDT Fri Jul 11 2025 Areas affected...central MS Concerning...Heavy rainfall...Flash flooding possible Valid 111828Z - 112228Z Summary...Convection is growing in scale and could align along a west-northwest to east-southeast axis shortly. Hourly rain amounts to 3" with local totals to 5" are possible, which could lead to flash flooding in urban areas. Discussion...Thunderstorms across MS over the past couple hours have been forming in a very moist and unstable environment, with precipitable water values of 2-2.25" and ML CAPE in western MS above 3500 J/kg. Westerly flow in the low-levels has been steering convection generally west to east, but radar imagery is implying the beginning of a cold pool forming across east-central MS. Effective bulk shear is 15-20 kts, which appears sufficient to lead to loose organization. The expectation is for an outflow boundary to shift south and somewhat westward with time, which should lead to a more northwest to southeast alignment with time downwind of the instability pool, which should retrograde somewhat farther in the next several hours. While hourly rain totals to 3" are possible, there's evidence that at least one location near Louisville MS managed 2" in 26 minutes, likely due to the strong instability present, which would bring instantaneous rain rates to 5"+. The 12z HREF probabilities of 0.5"+ appears to be doing a much better job than the 06z RRFS probs in this area. Hourly amounts to 3" with local amounts to 5" could cause flash flooding, particularly within urban areas. Roth ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!-7UT_kAtlZUQ5Daf03T1A48rQA6yNsDwqrK3Jy36QvQbuIPOSGEqc0ltEx_egj1ZN8HL= tmU4eRCovDDSLU0CboudA3k$ for graphic product... ATTN...WFO...JAN...MOB... ATTN...RFC...ALR...ORN...NWC... LAT...LON 33298971 32788860 31748855 31488939 31799030=20 32519079 33139051=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 3.20-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .