Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Wed Aug 09 2023 22:07:47 AWUS01 KWNH 092207 FFGMPD TNZ000-MOZ000-ARZ000-OKZ000-KSZ000-100406- Mesoscale Precipitation Discussion 0897 NWS Weather Prediction Center College Park MD 607 PM EDT Wed Aug 09 2023 Areas affected...southern Missouri, northern Arkansas, northeastern Oklahoma, far southeastern Kansas Concerning...Heavy rainfall...Flash flooding likely Valid 092206Z - 100406Z Summary...Deep convection is developing along western portions of the discussion area (southwestern Missouri, northeastern Oklahoma) currently. As these storms mature, localized training of cells should pose a flash flood risk especially in sensitive areas/low spots. Discussion...A couple of mid-level shortwave troughs apparent in satellite imagery across northwestern Missouri and central Kansas were likely helping to initiate deep convection along a slow-moving surface boundary extending from Bartlesville, OK to Springfield, MO to south of Rolla, MO. These storms are forming in a very unstable environment characterized by 2000+ J/kg MLCAPE and 7+ C/km mid-level lapse rates. Additionally, strong low-level flow and convergence along the aforementioned surface boundary was helping updrafts overcome minimal remaining inhibition from prior convection. Flow fields aloft were generally west-southwesterly and parallel to the initiating surface boundary, suggesting that convective training will become common as storms continue to mature. Additionally, the heavier rainfall is likely to fall across areas of southern Missouri and northern Arkansas that have received 2-5 inches of rainfall earlier today. With wet grounds and the expected training of convection on at least a localized basis, increasing flash flood potential is apparent. Over time, models (particularly CAMs) suggest that upscale growth into linear segments will likely occur, although backbuilding along the front and across the unstable air mass ahead of the front should also contribute to training and prolonged heavy rain potential. Also, southwesterly flow at 850mb should impinge upon an outflow boundary across northeastern Arkansas, which should allow for northeastward retreat of that boundary toward the MO/AR border while also potentially serving as a focus for additional convective development. FFG thresholds are in the 1-2 inch/hr range (lowest in southwestern Missouri) and latest thinking is that areas of 2-3 inch/hr rain rates should eclipse those thresholds at times. Convective development (and heavier rainfall) should reach the Mississippi River through the 01-03Z timeframe.=20 Cook ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!5xIOQxh1nqmZ5eZGCdSVIbxumWWGluyUaDuiDFx7VBvtgmNA9XfQvkP77zAPW5y2O2hj= HFXGtV2URV3vo9tZgGXA5XQ$ for graphic product... ATTN...WFO...ICT...LSX...LZK...MEG...PAH...SGF...TSA... ATTN...RFC...ABRFC...LMRFC...MBRFC...NCRFC...NWC... LAT...LON 38099169 37568998 36968960 35938969 35149061=20 35049328 35469574 36629642 37749471 38029365=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) .