Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Wed Aug 14 2024 06:52:05 AWUS01 KWNH 140652 FFGMPD MOZ000-ARZ000-141250- Mesoscale Precipitation Discussion 0879 NWS Weather Prediction Center College Park MD 250 AM EDT Wed Aug 14 2024 Areas affected...Southwest to South-Central MO...North-Central to Northeast AR Concerning...Heavy rainfall...Flash flooding likely Valid 140650Z - 141250Z SUMMARY...Areas of showers and thunderstorms will be developing and expanding in coverage over the next several hours across portions of southwest to south-central MO. Eventually this activity will also impact north-central to northeast AR. Significant cell-training concerns along with extremely heavy rainfall rates are expected to drive a strong threat for flash flooding going into Wednesday morning. DISCUSSION...A look at the overnight GOES-E Proxy Visible satellite imagery shows an increasingly agitated axis of CU/TCU across areas of far eastern KS on down through southern MO as weak warm air advection/isentropic ascent coupled with proximity of a strong elevated instability gradient sets the stage for convection to initiate. MUCAPE values are on the order of 2000 to 3000 J/kg across areas of far eastern KS and southwest MO right now, with a well-defined northwest to southeast oriented instability gradient that is aligned northeast of a quasi-stationary front. Over the next few hours there will be a gradual increase in low-level southwest flow over this boundary which should strengthen the isentropic ascent further and combine with the favorable thermodynamic environment for expanding clusters of heavy showers and thunderstorms. This will be facilitated by the eastward advance of shortwave energy/MCV activity along the KS/NE border which should help gradually increase the southwest flow around its southeast flank across eastern KS and into western MO. The mean steering flow over southwest to south-central MO is roughly about 20 kts from the west-northwest and is favorably parallel to the elevated instability gradient and frontal orientation for what should be a significant concern for cell-training later in the night and into Wednesday morning as convection develops and expands in coverage. PWs across the region are deeply tropical in nature with 00Z RAOB data and recent NESDIS Blended TPW data showing values up around 2.0 to 2.2 inches. CIRA-ALPW and RAOB data show strong concentrations of moisture deep through the column and this coupled with the instability profiles should yield convection this morning that will be capable of being very efficient and capable of extremely heavy rainfall rates that reach 2 to 3 inches/hour with the stronger storms. The 00Z HREF guidance shows quite a bit of spread with the placement of the heaviest rainfall and the amounts this morning, but suggests some extreme rainfall potential with the 00Z NAM-conest and 00Z ARW quite aggressive with their QPF. For now, given the set-up, the expectation is that some localized swaths of 3 to 6+ inches of rain will be possible going through the 12Z to 13Z (7AM to 8AM CDT) time frame. Flash flooding will become likely as a result, and locally significant impacts cannot be ruled out going into Wednesday morning. Orrison ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!8PseAleNxFhsHHs3CdAHNgb6siOpYatnvFzFPMDzPgAd6oDJ6gOIIW8nu79DC1G0RbT-= Eu2LI7B93c49az2sz3Lyqvw$ for graphic product... ATTN...WFO...EAX...LSX...LZK...MEG...PAH...SGF... ATTN...RFC...LMRFC...MBRFC...NCRFC...NWC... LAT...LON 38799388 38699310 38019185 37169063 36318999=20 35639005 35519077 35809176 36269250 37029358=20 37959433 38519433=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) .