Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sat Mar 15 2025 08:24:40 AWUS01 KWNH 150824 FFGMPD ALZ000-MSZ000-151122- Mesoscale Precipitation Discussion 0060 NWS Weather Prediction Center College Park MD 423 AM EDT Sat Mar 15 2025 Areas affected...northeastern Mississippi and northwestern Alabama Concerning...Heavy rainfall...Flash flooding possible Valid 150822Z - 151122Z Summary...Localized 1.5-2.5 inch/hr rain rates should continue for the next couple hours or so. Convective evolution thereafter is a bit uncertain. Isolated flash flooding is possible. Discussion...A dominant, right-moving supercell has persisted for several hours while reaching Itawamba County, Mississippi near the MS/AL border. This supercell has maintained broad rotation within a moist and strongly sheared airmass. Convection immediately upstream (along and north of its gust front) has enabled a scenario for localized training and rain rates approaching 2 inches/hr from near Okolona, MS northeastward to near Fulton, MS. As his lead supercell progresses into Alabama, increasing convective coverage has materalized upstream in areas near Tupelo, Columbus, and Greenwood. The cells are embedded within strong, broadly confluent 850mb flow exceeding 45 knots areawide, which continues to maintain moist/unstable thermodynamic profiles in the immediate wake of the supercell. It appears that this confluent low-level jet structure should be maintained for mutliple hours this morning despite 1) departing forcing for ascent with a mid-level vort max moving away toward the upper Midwest and 2) renewed mid-level troughing across Texas that should result in a gradual backing of 850mb flow. The ongoing supercell along the MS/AL border should eventually weaken as it reaches less stable air especially across north-central/northeastern Alabama. Upstream convection, however, should continue to support localized runoff issues as 1-hour FFG thresholds (in the 1.5-2 inch range) are approached by localized repeating/training cells across the discussion are through the morning - especially in areas that have already had rainfall.=20 Isolated flooding is possible, although this event appears to be perhaps the beginning of a more synoptically evident flash flood event expected to unfold later today/tonight. Cook ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!7eCMpjSSgxklFtbZy5khg8whhCUDdbCxFysQ5KngdLyj_VimEKCIqmbL2B7FmnAwhFAD= 7iMELL4PgcC3C1toe7e7W1s$ for graphic product... ATTN...WFO...BMX...HUN...JAN...MEG... ATTN...RFC...LMRFC...SERFC...NWC... LAT...LON 34998775 34638646 34078673 33678809 33918976=20 34758916=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) .