Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Wed Apr 26 2023 16:02:37 AWUS01 KWNH 261602 FFGMPD TXZ000-OKZ000-262200- Mesoscale Precipitation Discussion 0208 NWS Weather Prediction Center College Park MD 1201 PM EDT Wed Apr 26 2023 Areas affected...Extreme Southern OK...North-Central to Northeast TX Concerning...Heavy rainfall...Flash flooding possible Valid 261600Z - 262200Z SUMMARY...A localized and mostly urban flash flood threat will be possible over the next several hours from showers and thunderstorms with intense rainfall rates. DISCUSSION...The latest GOES-16 IR satellite imagery shows a well-organized cold-topped convective cluster advancing east across portions of the Red River Valley in association with the gradual southeast advance of strong height falls out into the southern High Plains. Radar trends have been showing a general increase in convective coverage and intensity over the last few hours as stronger large-scale forcing/divergence aloft arrives and interacts with the nose of a relatively moist and unstable 30 to 40 kt low-level jet overrunning a warm front. MUCAPE values of around 1000 to 1500 J/kg are noted up across areas of northern TX ahead of upstream surface low pressure, and the evolving MCS activity is well-entrenched along the northern edge of the elevated instability gradient. Over the next several hours heading through the afternoon time frame, the convective mass is likely to become rooted closer to the surface warm front lifting gradually northeast across central TX, with the development of additional and more discrete convective cells out ahead of it given the combination of increasing instability near the warm front and favorably strong shear profiles characterized by 40 to 50 kts of effective bulk shear. Some modest increase in the low-level jet will facilitate this as well. The 12Z HREF guidance and numerous runs of the HRRR this morning have been largely struggling with the placement and level of convective organization seen over the last few hours, with tendencies to be too slow and too far north into southern OK with the activity. However, they all do agree on an increased convective focus across north-central to northeast TX going into the afternoon hours. Expect the rainfall rates to be on the order of 1 to 2 inches/hour with the stronger cells, and the radar imagery does suggest some potential for some episodic repeating/training of cells that may favor some additional rainfall totals of as much as 3 to 4 inches going through mid to late-afternoon hours. The flash flood threat is expected to be localized in nature and largely confined to the more sensitive/hydrophobic urban areas including the Dallas-Forth Worth (DFW) metropolitan area. Some areas earlier this morning across the southeast suburbs of the DFW metro area did see heavy rains with as much as 2 to 3 inches falling. These areas will be impacted again over the next few hours and should also be a bit more sensitive to runoff concerns with the additional rainfall. Orrison ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!88T67WlrYThljoqIYDgTgbuTJs9r_EVO9gZb0GaDOhutRCllhJ4-VTcR_5Qpkny_xXRT= fA9BbkKs7_aVqDLn17KwhGQ$ for graphic product... ATTN...WFO...FWD...OUN...SHV...TSA... ATTN...RFC...ABRFC...LMRFC...WGRFC...NWC... LAT...LON 34129677 33909580 33489521 32919492 32239496=20 31729547 31589640 31709717 32149799 32629846=20 33059850 33469807 34049751=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) .