Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Mon Nov 04 2024 17:22:20 AWUS01 KWNH 041722 FFGMPD MOZ000-ARZ000-TXZ000-OKZ000-KSZ000-042320- Mesoscale Precipitation Discussion 1123 NWS Weather Prediction Center College Park MD 1221 PM EST Mon Nov 04 2024 Areas affected...Eastern OK...Northwest AR...Far Southeast KS...Southwest MO Concerning...Heavy rainfall...Flash flooding likely Valid 041720Z - 042320Z SUMMARY...Heavy showers and thunderstorms will gradually become more concentrated and organized by mid to late afternoon across eastern OK which will also impact portions of northwest AR, far southeast KS and southwest MO by this evening. Locally wet antecedent conditions and the additional rainfall will likely result in areas of flash flooding. DISCUSSION...A strong deep layer trough and associated closed low ejecting out of the southern Rockies will be interacting with a very moist and increasingly unstable airmass pooling north across the Red River Valley of the South, and will be setting the stage for a more organized and concentrated convective outbreak by mid to late afternoon across areas of eastern OK and eventually advancing into far southeast KS, northwest AR and southwest MO by early this evening. Many of these areas have already seen heavy rainfall over the last couple of days, and the arrival of additional rounds of strong convection and heavy rainfall rates will promote a likelihood for seeing additional flash flooding concerns. The latest surface analysis shows a cold front gradually shifting east across the Red River Valley of the South with a wave of low pressure seen crossing through central OK. Meanwhile, a warm front is noted out ahead of this stretching across eastern OK and into northwest AR. MLCAPE values of 1500+ J/kg have already pooled up across southeast OK and far western AR with 40 to 50+ kts of effective bulk shear in place given the stronger wind fields arriving ahead of the upper trough. Already the latest GOES-E visible satellite imagery shows a substantial amount of cloud street activity over eastern OK and this is suggestive of increasing boundary layer instability with a strong low-level jet. CIRA-ALPW data shows notably concentrated moisture in the low-levels of the column with enhanced layered vapor transport (LVT) seen extending up through northeast TX, eastern OK and western AR. This is being facilitated by a southerly low-level jet of 40 to 50 kts. This moisture transport coupled with the instability and shear should favor an environment conducive for enhanced rainfall rates. As height falls associated with the upper trough arrive this afternoon, a combination of DPVA/divergent flow aloft and the favorable thermodynamic and kinematic environments will support the development of more focused/organized convection which will likely include embedded supercell activity. Rainfall rates will be capable of reaching 1.5 to 2.5 inches/hour with the more organized cells, and as convection grows upscale this afternoon and early this evening, some additional storm totals may reach 2 to 4 inches which is supported by the 12Z HREF guidance. The wet antecedent conditions coupled with these additional rains will likely result in more concerns for flash flooding by late afternoon or early this evening. Orrison ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!95vqJy86OmPuqhXcuLKln84-u1AkcPL89a_zxTnBQgrSnqC1KOAuuJfHhfXvAydRDGQd= VD5W9jBLYO2dYZASnpyjkfU$ for graphic product... ATTN...WFO...FWD...ICT...LZK...OUN...SGF...SHV...TSA... ATTN...RFC...ABRFC...LMRFC...MBRFC...NWC... LAT...LON 37609449 37279352 36209347 34739408 33879507=20 33969662 34659700 35739666 36809615 37439530=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 3.20-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .