Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Fri Jun 16 2023 22:43:21 AWUS01 KWNH 162243 FFGMPD TNZ000-ALZ000-MSZ000-ARZ000-170441- Mesoscale Precipitation Discussion 0503 NWS Weather Prediction Center College Park MD 642 PM EDT Fri Jun 16 2023 Areas affected...eastern Arkansas, much of Mississippi, and much of western/central Alabama Concerning...Heavy rainfall...Flash flooding likely Valid 162241Z - 170441Z Summary...Ongoing clusters of heavy-rain-producing storms in northeastern Mississippi should continue to expand in coverage through the early overnight hours. Training and cell mergers should both support flash flood potential with this activity. Discussion...Earlier convection across the Mid-South has expanded a bit while favorably orienting for training across northeastern Mississippi in the past 1-2 hours. Cells in far northern Mississippi are still slow-moving, while newer convection from Tupelo to west of Tuscaloosa have become more robust while producing local 1-3 inch/hr rain rates. The southward development of the cells appear to be influenced by slightly stronger mid-level flow which should ultimately allow for faster storm motions, although the risk of training/repeating along the aforementioned Tupelo/Tuscaloosa axis seems to point to a locally enhanced flash flood threat over the next 1-2 hours. The 12Z high-resolution NAM (3km) seems to have a decent handle on convective evolution so far this evening. That model supports continued southward development with ongoing activity in northern Mississippi, while additional storms form in the open warm sector - perhaps as far west as the Mississippi River or even far eastern Arkansas. This solution seems plausible - objective analyses indicate mid-level shortwave troughs migrating southeastward to potentially further instigate convection while also depicting robust warm-sector instability (~3000 J/kg MLCAPE), abundant moisture (1.7+ inch PW values), and modest deep shear (40+ knots) for at least loosely organized clusters. While there is modest uncertainly on how the ongoing scenario should play out, the combination of both training cells and cell mergers should support local rain rates exceeding 2 inches/hr on a widespread-enough basis for flash flooding. Storms should make a gradual southward trek toward central Mississippi/central Alabama over the next 4-6 hours as well. FFGs are in the 1.5-2.5 inch/hr range - lowest across eastern Mississippi where copious amounts of rain (5+ inches) have fallen over the past week. The expected rainfall rates are likely to result in a few areas of flash flooding through the early overnight hours. Cook ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!8Pu-dkZlT_C8aHJXhYVXRfTO7M3HVIxAYPsjRKcNFWHR7-yHM2eaojyJ48h1oau3yPN0= 66dsl2HyxjfZto832R4xavc$ for graphic product... ATTN...WFO...BMX...HUN...JAN...LZK...MEG...MOB... ATTN...RFC...LMRFC...SERFC...NWC... LAT...LON 35169091 34888964 34458821 34008723 33318687=20 32648665 31918670 31158745 30928855 31489019=20 33269121 35129191=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) .