Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Fri May 05 2023 20:58:36 AWUS01 KWNH 052058 FFGMPD ALZ000-MSZ000-LAZ000-060125- Mesoscale Precipitation Discussion 0224 NWS Weather Prediction Center College Park MD 457 PM EDT Fri May 05 2023 Areas affected...central Gulf Coast Concerning...Heavy rainfall...Flash flooding possible Valid 052055Z - 060125Z Summary...Short term training of heavy rain will have the potential to generate 2-4 inches of rain in 1-2 hours across portions of southeastern LA, southern MS and far southwestern AL. Localized flash flooding may result over the next few hours. Discussion...2030Z radar imagery over southern MS showed a bow echo tracking southeastward at 30-40 kt along its apex, located north of a warm/stationary front that extended northwestward through southeastern LA. Additional activity in the form of showers was noted between the leading edge of the bow echo/related outflow and the synoptic scale frontal boundary. Despite stable wave clouds on visible imagery over far southwestern AL into adjoining MS, the airmass has mostly recovered after early morning convection which produced 1-3 inches of rain from southeastern LA into coastal MS/AL, and lift with the advancing line of thunderstorms should be able to overcome lingering weak low level convective inhibition. The 20Z SPC mesoanalysis indicated 500 J/kg MLCAPE just west of Mobile Bay increasing to over 2000 J/kg near Lake Pontchartrain along with anomalous precipitable water values that ranged from 1.5 to 1.9 inches. Overrunning in the presence of sufficient instability should allow for increasing showers and thunderstorms over southeastern LA into southern MS over the next 1-2 hours, just ahead of the bow echo as it continues to track southeastward along the instability gradient. While individual cell movement is forecast to be from the west and northwest, upstream development could allow for short term training of cells with 2-4 inches of rain in a 1-2 hour time period given the environment in place. Overlap of these high rates with urban locations or with areas which received heavy rain from this morning, localized flash flooding may result. Otto ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!6eNQ3v402C7-tSIx06_ajGkjtz9DTEfUAGCinfxfnjiiDODdZD7Ai9a4Rsr_YK2EgWoV= XUrHoc-psFuTsJj-1BcdDtM$ for graphic product... ATTN...WFO...JAN...LIX...MOB... ATTN...RFC...LMRFC...SERFC...NWC... LAT...LON 31258892 30878810 30268792 30008848 29638919=20 29638997 30049053 30529059 31049033=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) .