Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Mon May 19 2025 05:42:31 AWUS01 KWNH 190542 FFGMPD TNZ000-ALZ000-MSZ000-190940- Mesoscale Precipitation Discussion 0287 NWS Weather Prediction Center College Park MD 140 AM EDT Mon May 19 2025 Areas affected...Northern MS and Northern AL Concerning...Heavy rainfall...Flash flooding possible Valid 190540Z - 190940Z SUMMARY...A locally training band of showers and thunderstorms with high rainfall rates will continue to impact portions of northern MS while gradually moving east into downstream areas of northern AL over the next 2 to 3 hours. DISCUSISON...The latest radar imagery shows a broken band of heavy showers and thunderstorms traversing portions of northern MS (especially north of Tupelo) with an alignment north of a quasi-stationary front. This convection which is effectively a small-scale MCS has been rather long-lived at this point and continues to move east along a well-defined instability gradient pooled along the front. There continues to be as much as 1500 to 2000 J/kg of MLCAPE over areas of northeast MS through northern AL, and the convective mass will likely tend to be sustainable for at least a few more hours given favorable low-level moisture convergence nosing in along the southwest flank of the convection where warm air advcetion is more pronounced. Additionally, there is proximity of at least a weak MCV near the MS/TN border which should favor at least some modest mid-level forcing. Rainfall rates with this MCS have had a history of being quite high and upwards of 1.5 to 2.5 inches/hour. Over the next 2 to 3 hours, the RRFS which has the best handle on this system (albeit a tad too far north), suggests an eastward extension of heavy convective rains that would allow for northern AL to be impacted. Some of these areas in general across northern MS and northern AL are quite moist from recent rainfall, and the arrival of as much as another 2 to 3+ inches of rain may allow for some runoff concerns and at least an isolated threat for flash flooding. This will especially be the case over northern AL where there is some locally higher/sloped terrain and thus potential for more efficient runoff given the high rainfall rates. Areas that will likely be impacted over the next 2 to 3 hours will include Muscle Shoals and eventually the Huntsville vicinity. Orrison ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!6RHvC0rpznoIBbk7DBnOZeZT79lcZCMUj_ebjgFNtpBftmrY9X_oU-BE89KIKfhXI_xR= SoNrjNxPcDM1s9NeWZ8ze0Q$ for graphic product... ATTN...WFO...BMX...HUN...MEG...OHX... ATTN...RFC...LMRFC...SERFC...NWC... LAT...LON 35068805 35068653 34918569 34388579 34158810=20 34258924 34488983 34848987 35038910=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 3.20-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .