Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Wed Jul 05 2023 04:41:44 AWUS01 KWNH 050441 FFGMPD GAZ000-TNZ000-ALZ000-050830- Mesoscale Precipitation Discussion 0639 NWS Weather Prediction Center College Park MD 1240 AM EDT Wed Jul 05 2023 Areas affected...Middle TN into northern AL, far northwest GA Concerning...Heavy rainfall...Flash flooding possible Valid 050433Z - 050830Z SUMMARY...Isolated flash flooding will remain possible across portions of Middle TN into northern AL and perhaps far northwestern GA through 08Z. Slow moving areas of heavy rain will continue to produce 1-2 in/hr in the short term but if further weakening trends continue over the next couple of hours, the flash flood threat could end sooner. DISCUSSION...Regional radar imagery at 0415Z showed a small cluster of thunderstorms tracking eastward across south-central TN, along and just north of the AL border. An MCV was noted over Wayne County with an average movement toward the ENE at 20-25 kt since 02Z. Infrared satellite imagery has shown a overall weakening trend over the past 1-2 hours via warming cloud tops, but localized new thunderstorm development continued along and just ahead of the MCV over eastern Wayne, Lawrence and northeastern Lauderdale counties. Upward trends in isolated and disorganized cells over northern AL have also been observed between Decatur and Gadsden, AL, forced in part by an increase in low level flow with area VAD wind plots at 850 mb showing south to southwest near 10 kt, perhaps locally higher just ahead of the MCV. The moist (PWATs of 2.0 to 2.1 inches) and unstable (MLCAPE ~1000 J/kg) environment is expected to support continued development of slow moving thunderstorms ahead of the MCV for at least another hour, but increasing low level convective inhibition could limit updraft development beyond 05/06Z. On the other hand, there is low end potential for cells to continue to grow and expand locally within a narrow corridor of uninhibited instability immediately downstream and southeast of the MCV as it tracks toward the ENE, potentially producing 1-2 in/hr rates and localized additional rainfall totals of 2-3 inches. These rates could surpass area flash flood guidance of 1.5 to 2.5 in/hr and 2.5 to 3+ in 3 hours over the next few hours. Trends will continue to be monitored with this area given mixed signals in recent CAM guidance. Otto ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!9BInpegSq25H9pWQe7GKjUgg4vXfxDdvWfZ4nVFiLIxsYeoWY-kEncxtvXkkSPJyNBJ2= cebTWifqm36tM2mUwmY_Ss4$ for graphic product... ATTN...WFO...BMX...FFC...HUN...MRX...OHX... ATTN...RFC...LMRFC...OHRFC...SERFC...NWC... LAT...LON 36238605 36158505 35218480 33998599 33988695=20 34708715 35018764 35508781 35858721=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) .