Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Thu Aug 28 2025 14:55:55 AWUS01 KWNH 281455 FFGMPD ARZ000-OKZ000-281900- Mesoscale Precipitation Discussion 1019 NWS Weather Prediction Center College Park MD 1055 AM EDT Thu Aug 28 2025 Areas affected...central/eastern OK into western/central/southern AR Concerning...Heavy rainfall...Flash flooding likely Valid 281454Z - 281900Z SUMMARY...Areas of training with rain rates ranging between 1 to 3 in/hr are expected to produce areas of flash flooding from portions of eastern OK into western AR through 19Z. Additional rainfall over the next 4 hours should range between 2 to 4 inches, but localized higher totals cannot be ruled out. DISCUSSION...Radar imagery from 1420Z showed an elongated axis of elevated thunderstorms stretching from central OK into western AR, along with a secondary axis of NW to SE training from central AR into central MS. Since 12Z, embedded areas of training within this broad axis have shown hourly rainfall between 1-2 inches, but locally in excess of 2 inches as well. A convectively enhanced vorticity max was observed in water vapor imagery just southeast of Wichita, KS with movement toward the southeast. MUCAPE values to the northeast of a frontal boundary (extending from central OK into eastern TX) were a modest 500 to 1000+ via 14Z SPC mesoanalysis data but were likely "tall/skinny" with PWAT values compensating with estimated values near 2 inches within the ongoing convective axis. VAD wind data showed 925-850 mb winds overrunning the surface front with 25-35 kt of flow from the southwest. A recent southward push to thunderstorms over central OK were minimizing the flash flood threat across that portion of the state but new development downstream was showing signs of training with the coldest cloud tops on IR imagery from eastern OK into western AR. While forecasts from the RAP indicate a steady weakening of the 825-850 mb flow into the 15-20 kt range by 19Z, areas of flash flooding will be likely to sustain in the short term. Over the next 3-4 hours, forcing for ascent will continue to come from a combination of isentropic ascent atop the front, DPVA ahead of the advancing vorticity max positioned over southern KS and diffluent flow aloft within the anomalously moist environment. Hourly rainfall of 1-2 inches will be common within areas of training but isolated hourly totals of 2 to 3 inches may also occur. The greatest concern will be from eastern OK into western AR where an additional 2 to 4 inches of rain (locally higher) is expected through 19Z. Otto ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!8avPSJ6cwdAZzHG7igoooXKdXQjxus8-hAHKmHcWhIzu7bO69r6n8DxVE5oSIzUXiQXz= uU-Pe5uQnoAr-uU58pKgA1U$ for graphic product... ATTN...WFO...JAN...LZK...OUN...SHV...TSA... ATTN...RFC...ORN...TUA...NWC... LAT...LON 36399520 35839394 35399297 34959201 34279136=20 33579137 33339229 33709400 33999518 34399642=20 34859707 35199730 35859696 36389581=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 3.28-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .