Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Tue Jan 03 2023 15:34:34 AWUS01 KWNH 031534 FFGMPD PAZ000-VAZ000-WVZ000-OHZ000-TNZ000-KYZ000-ALZ000-032100- Mesoscale Precipitation Discussion 0011 NWS Weather Prediction Center College Park MD 1033 AM EST Tue Jan 03 2023 Areas affected...Portions of the OH Valley and Mid-South Concerning...Heavy rainfall...Flash flooding possible Valid 031532Z - 032100Z SUMMARY...Broken lines of heavy showers and thunderstorms will continue going through mid-afternoon. Additional areas of flash flooding will remain possible given locally intense rainfall rates and areas of repeating cell activity. DISCUSSION...Ongoing broken lines of heavy showers and thunderstorms continue to evolve across areas of the OH Valley and down through the Mid-South well ahead of a cold front and associated deep layer trough traversing the Midwest. Very anomalous moisture transport continues across the region given presence of a strong low-level jet approaching 50+ kts. In fact, 850/700 mb moisture flux anomalies are on the order of 3 to 5 standard deviations above the mean, and with PWs of 1.25 to 1.5 inches, the ongoing convective segments are rather efficient with rainfall rates that are still locally as much as 1 inch/hour. The downstream environment across areas of southern OH, western WV and eastern KY is quite marginal with respect to instability with MUCAPE values of only 250 to 500 J/kg at best. However, there is a rather strong degree of low-level convergence still ongoing near and just ahead of the convective activity which is being aided in part by favorable upper jet support ahead of the upstream trough over the Midwest. Over the next several hours going through mid-afternoon, there will actually tend to be some strengthening of the upper jet support with the RAP guidance suggesting a coupled jet structure riding northeast up across middle TN through east-central KY. There is somewhat better instability noted also farther south across middle TN (MUCAPE 500+ J/kg) which will attempt to ride up through areas of eastern KY, and the combination of this and the robust low-level jet should tend to sustain the convective threat across these areas. Given the moistening soil conditions from ongoing rains, and concerns of some additional repeating rounds of convection over the next several hours, there will continue to be a threat of additional areas of flash flooding heading into the afternoon hours with the greatest threat generally down across the Mid-South. Orrison ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!-FAB6qIwf5X346g-ErPDKwxZC_G9aZ42EhTCvObqyl6-TddQHmNInt7MF3aDIEgpN3Cu= VeCO7P_qK_kOkukv5pgN4Kc$ for graphic product... ATTN...WFO...HUN...ILN...JKL...LMK...MEG...MRX...OHX...PAH... PBZ...RLX... ATTN...RFC...LMRFC...OHRFC...NWC... LAT...LON 39968071 39558023 39108052 38358148 37028295=20 35598503 34968633 34498735 35158715 35608766=20 35858805 36338778 37178589 38568377 39558223=20 =20=20=20=20=20=20=20=20=20=20=20=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) .