Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Wed Nov 30 2022 10:04:02 AWUS01 KWNH 301003 FFGMPD FLZ000-GAZ000-ALZ000-MSZ000-LAZ000-301500- Mesoscale Precipitation Discussion 1140 NWS Weather Prediction Center College Park MD 503 AM EST Wed Nov 30 2022 Areas affected...southern Alabama, Florida Panhandle, southeastern Louisiana, southeastern Mississippi, and southwestern Georgia Concerning...Heavy rainfall...Flash flooding possible Valid 301001Z - 301500Z Summary...Ongoing storms pose an isolated flash flood risk for at least the next 2-4 hours. This risk may eventually begin to wane, although this will depend strongly on evolution of storms in southern/southwestern parts of the discussion area. Discussion...Convection continues as a mix of linear and cellular modes from central Alabama (near MXX) southwestward through Hattiesburg and the northern sides of Lake Pontchartrain. The orientation of the linear MCS across central Alabama (with backbuilding noted from near Meridian eastward) has yielded a local maxima in rainfall rates (exceeding 2 inches/hr in spots based on MRMS estimates) near the Talladega National Forest.=20 Additionally, training cells from Hattiesburg eastward through Washington County, AL have also resulted in peaked rainfall rates exceeding 2 inches/hr at times. Heavy rainfall was also noted farther southwest toward the northern parts of St. Tammany Parish - again due to favorable orientation of convection to westerly flow aloft for training/backbuilding. These conditions suggest a continued flash flood threat for at least the next 3 hours or so - especially in sensitive/urbanized areas and locales where 2+ inch/hr rain rates can materialize. Over time, the approach of a cold front and pre-frontal shift (both located across central/northern Louisiana and western Mississippi) and continued upscale growth of convection will allow for more/faster southeastward progression of storms. This process will be more pronounced across central Alabama, but may take longer to unfold from southeastern Louisiana through the Mobile Metro area and Florida Panhandle away from any synoptic or larger-scale boundaries. FFG thresholds are considerably higher with southeastward extent, exceeding 2.5 inches/hr south of US 80 and reaching 4 inches/hr closer to the coast and in the Florida Panhandle. The flash flood threat should continue through at least 13Z, though faster storm motions (via upscale growth of convection) and a more limited spatial extent for backbuilding might limit the risk somewhat - especially after 14Z or so. Cook ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!8p67wWa8S1M3nwdK2wcfsuIOQ7LjYo7smsS7gP8z7m3Z0mDLYs3w2HiKGoGeNdRFOSQN= Ag7PpQ6NmBBDt3HTwdNF9es$ for graphic product... ATTN...WFO...BMX...FFC...JAN...LCH...LIX...MOB...TAE... ATTN...RFC...LMRFC...SERFC...NWC... LAT...LON 32978582 32648484 31918411 30888389 30198403=20 29858450 29738509 30188572 30348672 30118859=20 29418902 29018933 29149051 29479143 29989129=20 30819039 31688896 32618717=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 3.14-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .