Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sun Jul 13 2025 17:57:44 AWUS01 KWNH 131756 FFGMPD PAZ000-MDZ000-VAZ000-NCZ000-WVZ000-TNZ000-132355- Mesoscale Precipitation Discussion 0671 NWS Weather Prediction Center College Park MD 155 PM EDT Sun Jul 13 2025 Areas affected...Central Appalachians and Mid-Atlantic Piedmont Concerning...Heavy rainfall...Flash flooding possible Valid 131755Z - 132355Z SUMMARY...Scattered showers and thunderstorms with very heavy rainfall rates will continue to develop and expand in coverage. Isolated to scattered areas of flash flooding will be possible going through the afternoon and into the evening hours. DISCUSSION...The latest GOES-E GeoColor RGB satellite imagery shows convection continuing to initiate and expand in coverage across portions of central NC through southwest and western VA. There will be additional areas of heavy showers and thunderstorms that will gradually develop further back across the central Appalachians with an expansion generally north near and west of the Blue Ridge including areas of eastern WV through western VA, the MD/WV Panhandles and large areas of southwest and central PA. Given strong diurnal heating near and adjacent to the terrain, MLCAPE values have increased to 1000 to 2000+ J/kg. Meanwhile, the column is very moist with the 12Z IAD RAOB showing a 2.14" PW and and a tall skinny CAPE profile that is strongly suggestive of warm/tropical rain processes. This will support enhanced rainfall rates with any thunderstorm activity this afternoon and this evening. Terrain-driven circulations/orographics and differential heating boundaries will tend to support a substantial amount of terrain focused convection over the next several hours given the level of moisture and instability in the column, but areas farther east over the Piedmont may also see convection become locally more expansive by later this afternoon. This will includes areas of central NC around the Raleigh-Durham area where a cluster of storms is noted just east of the city. Rainfall rates will be capable of reaching 2 to 3 inches/hour with the stronger storms, and with slow cell-motions, some spotty storm totals of 3 to 4+ inches will be possible by this evening. This is consistent with some of the 12Z HREF guidance. Isolated to scattered areas of flash flooding will be possible, and this will include areas of locally rugged terrain near the central Appalachians/Blue Ridge and also around any urbanized corridor that sees convection. Orrison ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!8y_Bz5FPdkJtHBQI6SyGqza8Qrc3tLsvrmHvhwBr1ULJtCfbA6dCsWOm08OE3uUlYMmw= 0L20HlyC8s7U2AwVw2-F9h0$ for graphic product... ATTN...WFO...AKQ...BGM...CTP...GSP...LWX...MHX...MRX...PBZ... RAH...RLX...RNK... ATTN...RFC...ALR...ORN...RHA...TIR...NWC... LAT...LON 41977730 41677671 39997736 39247725 38537739=20 37677744 36937667 35517739 35517855 36037966=20 36088062 36298229 37008256 38068089 39397954=20 40887868 41767804=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) .