Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Tue Apr 02 2024 17:33:53 AWUS01 KWNH 021733 FFGMPD VAZ000-WVZ000-OHZ000-TNZ000-KYZ000-INZ000-022300- Mesoscale Precipitation Discussion 0129 NWS Weather Prediction Center College Park MD 132 PM EDT Tue Apr 02 2024 Areas affected...much of KY and surrounding portions of WV, Middle TN, and southern OH Concerning...Heavy rainfall...Flash flooding possible Valid 021730Z - 022300Z Summary...Narrow swaths of 2-4" of rainfall may occur through mid-afternoon, possibly resulting in isolated to scattered flash flooding. Discussion...Relatively disorganized convection is ongoing early this afternoon across a broad warm sector, encompassing much of the MS/OH/TN Valleys. Some of the most efficient multicell clusters have developed across the OH/TN Valley over the past several hours, producing up to 1"/hr accumulations across portions of northern Middle TN and south-central KY. This convective activity looks to track into the wake of an earlier bow echo which raced across portions of northern KY, southern OH, and much of WV this morning, resulting in 0.5-1.0" of rainfall locally (and pre-saturating soils across much of the region). The mesoscale environment is characterized by 500-1000 J/kg of ML CAPE (and increasing by as much as 300-600 J/kg over the past 3 hours), precipitable water values of 1.1-1.6 inches (near or above the 90th percentile, per SPC sounding climatology), and ample deep layer shear of 50-60 kts. While convection within the open warm sector is expected to remain somewhat disorganized through mid-afternoon (primarily due to the lack of a focusing mechanism), cells may still take on an increasingly linear orientation (from WSW to ENE with the deep mean flow) that would allow for localized training through mid-afternoon. This could result in narrow swaths as high as 2-4" through mid-afternoon, as suggested by 12z HREF 40-km neighborhood exceedance probabilities of 20-50% and 5-10% for 2" and 3" thresholds, respectively. These totals would meet or exceed associated short-term (3-hr) FFGs of 1.5-2.5", suggesting that isolated to scattered instances of flash flooding are possible (particularly over northern portions of the outlooked area, where localized 0.5-1.0" totals occurred this morning). Churchill ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!6BdLnPLiJMuoYZcB0qxvsVZV92DcAUQRx1BKWavSYe80IacI8apjLFwN2oOSXV4wBQzq= jPKloxl7HRTqCRVMIW1no3Y$ for graphic product... ATTN...WFO...ILN...JKL...LMK...MRX...OHX...PAH...RLX...RNK... ATTN...RFC...LMRFC...OHRFC...NWC... LAT...LON 39108161 38938060 37948045 37518155 37178259=20 36758386 36348501 35898650 35908754 36558772=20 37458707 38178590 38718424 38938289=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) .