Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sun May 07 2023 23:40:35 AWUS01 KWNH 072340 FFGMPD TNZ000-KYZ000-INZ000-ALZ000-ILZ000-MOZ000-080537- Mesoscale Precipitation Discussion 0234 NWS Weather Prediction Center College Park MD 738 PM EDT Sun May 07 2023 Areas affected...Southern IL...Far Southwest IN...Western KY...Western/Central TN Concerning...Heavy rainfall...Flash flooding likely Valid 072337Z - 080537Z SUMMARY...Scattered instances of flash flooding are likely heading through the evening and overnight period across areas of the Lower OH Valley and Mid-South given the expectation of multiple rounds of heavy showers and thunderstorms. DISCUSSION...The latest surface observations show a long-lived cold pool from earlier MCS activity situated across a large area of the Lower Ohio Valley, with the main outflow boundary now situated northwest to southeast from western IL down through far western KY and into central TN. This is focused adjacent to a moderate to strongly unstable airmass pooling over areas of the Middle MS Valley and Mid-South where MLCAPE values of 1500 to 2500 J/kg are in place, and with PWs of near 1.5 inches. This outflow boundary has been a general focus for scattered to broken areas of redeveloping showers and thunderstorms over the last couple of hours, and the concern heading through the evening will be additional rounds of convection that will be capable of aligning itself and tracking in a general northwest to southeast fashion along and just east of the outflow boundary as persistent moist/unstable southwest low-level flow interacts with this cold pool and attempts to overrun it. Heavy rainfall rates of up to 2 inches/hour are expected with the stronger and more organized convective cells heading through the evening time frame, and with an environment conducive for cell-training, some localized storm totals going through midnight may approach 3 to 5 inches with isolated heavier amounts. The 12Z/18Z HREF guidance and recent HRRR runs all favor western KY down through central TN as being the axis of heaviest rainfall potential this evening, and there is some chance these models may be a bit underdone with their QPF given the cell-training threat and degree of instability lurking nearby over the Mid-South. Given the meteorological setup for convection, and with some areas already seeing locally wet antecedent conditions from earlier rainfall, scattered instances of flash flooding are considered likely this evening with the additional rounds of heavy showers and thunderstorms. Orrison ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!6FymZb5V4J4aANSN2SjEaonccgjuZ9FdnMQI38HGm81SO5_zhfNXKPqmHRQNABNIGKTM= Etnonu5_zBVom7UxVD5P1SE$ for graphic product... ATTN...WFO...HUN...ILX...IND...LMK...LSX...MEG...MRX...OHX... PAH... ATTN...RFC...LMRFC...NCRFC...OHRFC...NWC... LAT...LON 39888895 39468806 38298761 37218643 36318469=20 35168492 34908627 35358794 36608928 38368992=20 39488993=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) .