Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Tue Jul 22 2025 17:34:53 AWUS01 KWNH 221734 FFGMPD NCZ000-SCZ000-GAZ000-222215- Mesoscale Precipitation Discussion 0776 NWS Weather Prediction Center College Park MD 134 PM EDT Tue Jul 22 2025 Areas affected...central SC/GA to coast Concerning...Heavy rainfall...Flash flooding likely Valid 221729Z - 222215Z Summary...Scattered to numerous thunderstorm coverage across the Coastal Plain of SC/GA into inland locations through the afternoon will likely allow for at least isolated flash flooding. High rainfall rates will support the potential for 5+ inches of rain in one or two locations. Discussion...17Z visible imagery from GOES East showed a small cluster of thunderstorms located about 50 miles offshore of the Pee Dee coast of SC, along with rapid cumulus development across inland locations near and north of I-26. These areas of development were located near/north of a diffuse quasi-stationary front which draped east to west across southern SC. PW values were anomalous across the region (12Z CHS showed 90-95th percentile) and surface heating through mostly clear skies was contributing to MLCAPE values of 2000-3000 J/kg along with little to no convective inhibition per 17Z SPC mesoanalysis data. Continued thunderstorm development is likely over the next 1-3 hours in the vicinity of weak convergence associated with the quasi-stationary front, a developing sea breeze boundary and resultant outflows. Steering flow is very weak at 5 kt or less across the southern half of SC into GA, which will contribute to very slow cell motions. Low level flow oriented roughly parallel to the coast from the north and short term RAP development of a surface low in eastern GA should contribute to convective clusters evolving toward the south and west with time. While weak wind shear aloft will prevent organized thunderstorm development, slow movement, cell/outflow mergers and potential for at least brief upstream cell development are expected to allow for very high rainfall rates with 2-4 in/hr possible and perhaps sub-hourly totals of 1 to 2 inches in 15-30 minutes. While this area of the U.S. typically needs a lot of rain to cause flash flooding, these high rates could overlap with urban areas and there will also be potential for one or two areas to pick up 5+ inches of rain. These high rainfall values are expected to lead to at least isolated flash flood development. Otto ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!7okIpuGK6ckkevDQyXrY8smZotVcM4RCoRF-yvY81aTS47qRWSmQ661wbam9caYEqSGf= nbkLcUH5V7SCOV2bw1f2d_8$ for graphic product... ATTN...WFO...CAE...CHS...FFC...ILM... ATTN...RFC...ALR...NWC... LAT...LON 34157871 33747833 33157875 32237998 31838131=20 32338321 33258352 33738263 34088114 34047995=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 3.28-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .