Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Wed Apr 03 2024 03:09:02 AWUS01 KWNH 030308 FFGMPD NCZ000-SCZ000-GAZ000-ALZ000-030907- Mesoscale Precipitation Discussion 0132 NWS Weather Prediction Center College Park MD 1108 PM EDT Tue Apr 02 2024 Areas affected...portions of Alabama, Georgia, and western South Carolina Concerning...Heavy rainfall...Flash flooding possible Valid 030307Z - 030907Z Summary...Convective coverage was expanding across Alabama and west-central Georgia, and 1+ inch/hr rain rates were beginning to approach urbanized areas near Atlanta, GA and south of Birmingham, AL. Isolated instances of flash flooding are possible through 09Z. Discussion...The combination of broad low-level confluence across the discussion area and upper difluence was resulting in maturing convection across southwestern/central Alabama and west-central Georgia over the past couple of hours. SPC mesoanalyses indicated that storms were located in an unstable, yet weakly capped environment characterized by ~1500 J/kg SBCAPE, 1.5-2 inch PW values, and strong vertical shear/flow aloft. The flow aloft was keeping most convection progressive in nature, although convective orientation (more parallel to flow aloft) in a couple areas was resulting in training and rain rates exceeding 1 inch/hr - 1) west of Atlanta Metro (near Carrollton, GA) and 2) over Talladega National Forest near west of Selma, AL. FFG thresholds are generally in the 2.5 inch/hr range across most of the discussion area (locally lower in urban areas), suggestive of an isolated flash flood threat where ground conditions are relatively sensitive in the short term. Over time, three factors should contribute to a continued, gradual expansion of convective coverage through the night, including 1) an approaching mid/upper jet stream across currently across southeast Texas, 2) increasing low-level flow/persistent low-level confluence across the unstable airmass in place across the discussion area, and 3) destabilization into portions of northern Georgia and upstate South Carolina, where ground conditions are somewhat more sensitive for flash flood potential (lower FFGs).=20 Each of these factors suggest a continued risk of areas of rain rates approaching 2 inches/hr (especially where training is pronounced) along with a gradually increasing, yet isolated flash flood risk. Again, this risk is focused mainly from central Al into the Atlanta Metro area in the near term, but should spread northeastward into more of the southern Appalachians over the next 3-6 hours. Cook ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!6fUeuHG0re_PK2rdUinrDo1-JfIJcWPfLWyMlYG9P13VJs2eiUk7ERyKf2iVucMvrgz8= aqg4Qz1dNx2g3GEgSOk9TuE$ for graphic product... ATTN...WFO...BMX...CAE...FFC...GSP...HUN...MOB...MRX...TAE... ATTN...RFC...LMRFC...SERFC...NWC... LAT...LON 35258189 35078113 34448096 33768130 32828228=20 31998411 31338615 31358751 31598812 32118815=20 33078753 33818682 34658598 34928464 35218307=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 3.20-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .