Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sat Jul 19 2025 16:55:08 AWUS01 KWNH 191655 FFGMPD MDZ000-VAZ000-NCZ000-WVZ000-OHZ000-TNZ000-KYZ000-192253- Mesoscale Precipitation Discussion 0756 NWS Weather Prediction Center College Park MD 1254 PM EDT Sat Jul 19 2025 Areas affected...portions of the central Appalachians Concerning...Heavy rainfall...Flash flooding likely Valid 191653Z - 192253Z Summary...Scattered thunderstorms are developing atop sensitive ground conditions due to prior rainfall. These trends should continue through the early evening. Flash flooding is likely. Discussion...Scattered thunderstorms were gradually increasing in coverage and intensity across the area. The storms are in a weakly forced environment, although abundant moisture and instability (1.6-2 inch PW and 1000 J/kg MLCAPE) were supporting efficient rainfall processes with the deeper and more dominant convection. Weak westerly steering flow aloft was resulting in 15-20 knot storm motions that, when combined with the moisture/instability combo, were prompting areas of 0.5-1 inch/hr rain rates. These rates were already approaching suppressed FFG thresholds (generally in the 0.25-1 inch/hr range), highlighting sensitive ground conditions from abundant rainfall over the past few weeks. With several hours of peak heating left in the diurnal cycle, models/obs suggest that convection will continue to expand in coverage and intensity through the afternoon. The increase in coverage should result in greater chances for cell mergers and locally enhanced rainfall rates due to mesoscale convective processes. Spots of 1.5 inch/hr rain rates can be expected at times, which would readily exceed local FFG in most areas and result in locally significant flash flood potential. Much of this threat will be diurnally driven with flash flood potential persisting through 23Z/7p EDT. It is worth noting that deeper, organized convection across the Lower Ohio Valley will result in renewed/continued flash flood potential across the area, and this threat could extend beyond 23Z as a result. Cook ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!8MtLyCPs6g9qz0sv-VP69vsjOMHQBqqPZ_Q5YaFekp75mEIucfojHvfFW6pcRN-LDDjs= E1-xBnGhbmEWRLDUOEv4jOU$ for graphic product... ATTN...WFO...GSP...ILN...JKL...LWX...MRX...OHX...PBZ...RLX... RNK... ATTN...RFC...ALR...ORN...RHA...TIR...NWC... LAT...LON 39677952 39507829 39017791 38137832 37247932=20 36718033 36198196 35858399 36418476 37438421=20 38528308 39438103=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) .