Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sun Jul 09 2023 18:10:51 AWUS01 KWNH 091810 FFGMPD TNZ000-ALZ000-MSZ000-LAZ000-MOZ000-ARZ000-100000- Mesoscale Precipitation Discussion 0678 NWS Weather Prediction Center College Park MD 209 PM EDT Sun Jul 09 2023 Areas affected...Mid-South Concerning...Heavy rainfall...Flash flooding possible Valid 091810Z - 100000Z SUMMARY...Thunderstorms along an approaching cold front and closer to the Gulf Coast may cause areas of flash flooding this afternoon. DISCUSSION...Weak 500mb troughing over central AR and an approaching cold front to the north are providing both the lift aloft and the trigger at the surface to trigger thunderstorms this afternoon. RAP mesoanalysis in western and central TN show MLCAPE >1,000 J/kg and PWATs around 2". Farther south, PWATs are also around 2" but have managed to garner stronger surface based-heating. This resulted in MLCAPE ranging between 2,000-2,500 J/kg. 17Z surface analysis also showed a surface trough oriented NW-SE from northern MS to western AL is already acting as a trigger for a swath of heavy thunderstorms. This is likely to continue as RAP mesoanalysis shows a steady westerly 850mb moisture transport over southern AR and northern LA. Latest HRRR shows storms currently along the front with additional storms likely to form into central TN. With mean 850-300mb winds running parallel to the front and ongoing 850mb moisture transport, there could be instances of training thunderstorms across the southern half of TN this afternoon. Farther south, attention will be on the remnant MCS as it tracks into northern MS and an outflow boundary in northern LA. They should act to set for more robust thunderstorms later this afternoon. MRMS shows the storms in western TN and into southern MS/AL contained instantaneous rainfall rates of 3-4", showing the torrential rainfall rates these storms are capable of generating. Combined with these excessive rainfall rates, much of the area has picked up 300-400% of normal rainfall over the last 7 days. 1-hr FFGs are <2" in some of these areas as well. Flash flooding is possible again this afternoon, with locations containing more saturated soils, poor drainage spots, and urbanized communities most at-risk. Mullinax ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!-tsTZxpbf867HtTqqsbhzqRZDyOEEX62D0K9Tcs3XRZVaKw--0mB3RivznolRKdhAJhw= B2f9PcGNlpuD7iokuXKLrec$ for graphic product... ATTN...WFO...BMX...HUN...JAN...LZK...MEG...MOB...OHX... ATTN...RFC...LMRFC...OHRFC...SERFC...NWC... LAT...LON 36208807 35788653 34098693 32338697 31708841=20 31808985 32469132 33939144 35219089 35939029=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 3.14-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .