Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Tue Nov 29 2022 21:02:21 AWUS01 KWNH 292102 FFGMPD GAZ000-TNZ000-ALZ000-MSZ000-300300- Mesoscale Precipitation Discussion 1135 NWS Weather Prediction Center College Park MD 401 PM EST Tue Nov 29 2022 Areas affected...Northern AL...South-Central TN...Far Northwest GA Concerning...Heavy rainfall...Flash flooding likely Valid 292100Z - 300300Z SUMMARY...Repeating rounds of heavy showers and thunderstorms are expected heading through the remainder of the afternoon and into the evening hours. Areas of flash flooding will gradually become likely from resulting excessive rainfall totals. DISCUSSION...The latest radar and satellite imagery shows multiple rounds of heavy showers and thunderstorms advancing across central to northeast MS and into northern AL as strong to severe convection continues to develop and grow upscale across the broader Mid-South and Lower MS Valley region ahead of an upstream upper-level trough. Strong low-level moisture transport advancing northeast across the region coupled with a corresponding nose of elevated instability will continue to work in tandem with strengthening shear parameters and broadly divergent flow aloft to drive organized clusters of convection that will be capable of advancing downstream and repeating/training over the same area. The activity that is currently moving across northern AL and into south-central TN may be followed by additional rounds of convection going through especially the 21Z to 00Z time frame with the redeveloping activity over northern MS. Additionally, in time, there will be concerns a little farther south over north-central AL (near and to the north and west of the Birmingham metro area) to see organized and locally training rounds of convection. The activity well upstream over central MS is expected to advance downstream and drive this threat in the 00Z to 03Z time frame. Given the robust moisture transport and supercellular nature of the cells, some enhanced rainfall rates are expected with the convection. The PW environment is increasing with time, and the setup, along with supporting HREF guidance, favors rainfall rates that may reach or locally exceed 2 inches/hour. Overall, it does appear that the HRRR guidance and the earlier HREF solutions are too slow with their downstream convective propagation, as the latest radar trends would even suggest areas downstream over far northwest GA may need to be monitored as well heading into the evening hours. Given the repeating nature of the convection, some localized storm total amounts going through early evening may reach 3 to 5+ inches with the heaviest amounts likely focusing over northern AL. Despite relatively dry antecedent conditions, the enhanced rainfall rates and storm total potential over the next several hours is likely to result in areas of flash flooding. Any urbanized area will be most susceptible to runoff problems. Orrison ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!6G-_D4z4YOrwZ7b1XswKG7N9zsYRbnAlOzoMEw_N0664IsnuTWkKMsp7YwfHyJYfy0x6= wU5lBjBhwR4isy0KXaySJSc$ for graphic product... ATTN...WFO...BMX...FFC...HUN...JAN...MRX...OHX... ATTN...RFC...LMRFC...OHRFC...SERFC...NWC... LAT...LON 35578613 35328530 34808505 34198515 33538559=20 33168650 33108858 33598828 34068798 34658797=20 35098797 35438697=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) .