Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sat Sep 02 2023 08:29:24 AWUS01 KWNH 020829 FFGMPD ALZ000-MSZ000-021400- Mesoscale Precipitation Discussion 1024 NWS Weather Prediction Center College Park MD 428 AM EDT Sat Sep 02 2023 Areas affected...western AL into north-central MS Concerning...Heavy rainfall...Flash flooding possible Valid 020827Z - 021400Z Summary...Localized flash flooding will be possible over the next 3-6 hours from parts of western AL into north-central MS. Training with rainfall rates of 1-3 in/hr will be possible. Discussion...Trends in regional radar imagery over the past hour have shown a subtle uptick in warm topped showers extending from the central AL/MS border into north-central MS (ending 08Z). Weak low level convergence at the nose of southerly winds backing toward the southeast appears to be the main focus for the location of these showers. Steering flow oriented parallel to the SW to NW convergence axis will support the potential for training of cells. Precipitable water per recent GOES East satellite imagery and ground-based GPS sensors indicated values ranging between 2.1 and 2.4 inches over MS/AL. The showers were forming within a fairly narrow axis of weak SBCAPE (250 to less than 1000 J/kg) which was viewed on the 08Z SPC mesoanalysis from west-central AL into much of MS, east of an inverted surface trough extending through the lower/middle MS Valley. Locations in central to eastern AL did not have (and are not forecast to have) enough instability to support higher rainfall rates. Given weak to zero convective inhibition and the highly moist environment, the continued growth of showers, dominated by warm rain processes, is expected to occur over the next few hours. If the showers are able to mature into a few robust cells, there will be a high likelihood for southeast to northwest training which could contain rainfall rates of 1-3 in/hr. While the flash flood potential is expected to remain highly localized, portions of eastern MS into western AL received 2-5 inches of rain over the past 24 hours, lowering FFG to less than 2 in/hr in some locations. Overlap with these portions of MS/AL or other hydrologically sensitive locations will be the most likely locations for flash flooding over the next 3-6 hours. Otto ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!9oecLBR6Xx1ulPihOypJEWzcY_B91OglJZ1XLMsm5C-Azvtlp71im_lvIEcZekzDuhXm= 2QVWQzUtk6BzrzY7pEV3m8M$ for graphic product... ATTN...WFO...BMX...JAN...MEG...MOB... ATTN...RFC...LMRFC...SERFC...NWC... LAT...LON 34438912 33958792 32898718 32218784 32368894=20 32678994 33159074 33869069 34429006=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) .