Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Thu Mar 02 2023 00:25:00 AWUS01 KWNH 020024 FFGMPD OHZ000-TNZ000-KYZ000-INZ000-ALZ000-ILZ000-MOZ000-ARZ000-020430- Mesoscale Precipitation Discussion 0080 NWS Weather Prediction Center College Park MD 724 PM EST Wed Mar 01 2023 Areas affected...Portions of the Ohio and Tennessee Valleys Concerning...Heavy rainfall...Flash flooding possible Valid 020023Z - 020430Z SUMMARY...Increasing coverage of individual fast moving storms poses a localized isolated flash flooding risk before thunderstorms expand in coverage and likely align favorably for repeating training by mid-evening. A broader axis of 2-3" totals should increase risk for flash flooding in coverage and magnitude. DISCUSSION...Convection was developing in proximity to the main stem Ohio River shortly before 00Z along an axis of instability ahead of a cold front. MRMS was already showing localized 1 to 1.25 inch amounts in under an hour as of 02/00Z. The southwest to northeast orientation of the convection is aligned fairly closely to the mean flow ahead of an approaching cold front...setting up the possibility of repeat convection or training of cells across the area. Southerly winds across the Tennessee Valley will be drawing dewpoints approaching 60 degrees ahead of the front...suggesting localized downpours could still continue through 03Z or 04Z before instability weakens. HRRR guidance began suggesting some potential for an axis of heavy rainfall rates close to where MRMS guidance showed the heaviest rainfall ending at 00Z...and the latest runs show a decrease in the heavier rates shifting eastward during the evening. At the same time...additional convection with moderate to heavy rainfall moving out of Arkansas and southwestern Tennessee move over parts of the MPD area later in the evening. While the area is not quite as sensitive as areas of the west...and individual cells may be progressive enough...there is a risk that the ground will not be able to entirely absorb all the rain given the rainfall intensity and short-term amounts. MPD079 remains in effect until 230Z. Bann ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!962iCsDn0XxSfAxy5n7tcHEnE3B7GiaByanxQJfbHTe9REXepUjzcQtvHAHCl1nacgym= AJmDAvPE78MpaJV1laMSqFA$ for graphic product... ATTN...WFO...HUN...ILN...JKL...LMK...MEG...MRX...OHX...PAH... RLX... ATTN...RFC...LMRFC...OHRFC...NWC... LAT...LON 39408435 39028349 37908300 36788440 35958559=20 34688763 35458833 35778936 35799071 36399009=20 37058851 38238641 38868519=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) .