Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Wed Aug 09 2023 00:26:30 AWUS01 KWNH 090026 FFGMPD KSZ000-NEZ000-COZ000-090624- Mesoscale Precipitation Discussion 0893 NWS Weather Prediction Center College Park MD 826 PM EDT Tue Aug 08 2023 Areas affected...eastern Colorado, western Kansas, and southwestern Nebraska Concerning...Heavy rainfall...Flash flooding possible Valid 090024Z - 090624Z Summary...Scattered, slow-moving thunderstorms will continue to increase in coverage through the overnight hours. 1+ inch/hr rain rates are expected, which should result in at least an isolated flash flood risk. Discussion...Sustained low-level convergence just northeast of a surface low near PUB was fostering deep convective development generally from LIC to 2V5 and northward from there trough the Nebraska Sand Hills. The storms in Colorado are taking advantage of very steep mid-level lapse rates (8.5+ C/km) and southeasterly low-level warm advection of 60s F surface dewpoints, which has fostered nearly 3000 J/kg MLCAPE. Furthermore, 20-25 knot flow in the 700-500mb layer was enabling storm motions of around 10-20 knots while also fostering occasional storm splits and mergers.=20 The net result of this pattern has been spots of 1+ inch/hr rain rates - particularly with the dominant, right-moving supercell over Yuma County, CO. While the ongoing scenario supports an isolated flash flood threat in the near term, increasing storm coverage could allow for a few more areas of 1+ inch/hr rates to materialize over the next 2-6 hours or so. The increase in storm coverage is supported by 1) a vigorous mid-level wave over Wyoming approaching the region from the west and 2) increasing convergence/low-level flow over western Kansas in tandem with development of a nocturnal low-level jet.=20 Ultimately, one or two clusters of convection should migrate eastward toward western Kansas over time, with mergers and backbuilding (hinted at by CAMs) supporting continue heavy rain potential. FFGs are generally in the 1-1.5 inch/hr range, which should be eclipsed from time to time in a few locations through 06Z. Isolated flash flooding is possible through that timeframe. Cook ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!56dYKyMV70Mp3U5OIlxw9XACLMwOT0DNFCYRgz0h52tRPtkelQjxQRNMJov1FBkn_N-q= HHfHNCx1rs2bTLa_gBCZoZU$ for graphic product... ATTN...WFO...BOU...CYS...DDC...GID...GLD...LBF...PUB... ATTN...RFC...ABRFC...MBRFC...NWC... LAT...LON 41510211 41510057 40359965 38879943 38099999=20 38120249 38910408 40280397 41120291=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) .