Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Wed Mar 08 2023 23:57:08 AWUS01 KWNH 082357 FFGMPD TXZ000-OKZ000-090555- Mesoscale Precipitation Discussion 0090 NWS Weather Prediction Center College Park MD 656 PM EST Wed Mar 08 2023 Areas affected...North Texas...Far Southern Oklahoma Concerning...Heavy rainfall...Flash flooding possible Valid 082355Z - 090555Z Summary...Elevated thunderstorms may train/repeat this evening with 1-2"/hr rainfall rates. Isolated instances of flash flooding are possible, with the potential for localized totals up to 3-5". Discussion...A west-to-east axis of strong to severe elevated thunderstorms has developed this afternoon across portions of North TX and far southern Oklahoma (just south and in the vicinity of the Red River), producing rainfall rates of 1-2"/hr. Convergence along a stationary front between 850-700 mb is responsible for these storms, and warm advection is expected to continue with deep layer (0-6 km) bulk shear on the order of 40-50 kts. Precipitable water values range from 1.2-1.4 inches (near the max moving average, per FWD sounding climatology) with MU CAPE as high as 500-1000 J/kg. While the rain rates of 1-2"/hr are fairly tame for this portion of the country, the main concern is the repeating of these rates for several hours as both the deep layer mean wind and shear vectors are nearly parallel (with the mean wind from the west-northwest and the shear vector from the due west). Straight line hodographs are resulting in storm splitting, which should help to keep any instances of flash flooding somewhat isolated with training not completely efficient. The 18z HREF suite and subsequent HRRR runs have done a fairly bad job at depicting the ongoing convection. Most CAMs have been simply too weak with the initiation of elevated convection, as the satellite presentation has been rather impressive with ongoing distinct overshooting tops and associated IR signatures of -60 to -70 degC. The expectation is that this convection will continue through much of the evening, with some repeating of 1-2"/hr rainfall rates resulting in isolated 3-hr accumulations approaching 3-5 inches (exceeding local flash flood guidance, which is near 2 inches). The rather compact nature of the storm cores and resulting left and right movers from storm splits should keep these higher totals rather isolated, and confidence is low that the training of the storm tracks will align to result in flash flooding. Churchill ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!8NONyvKoIUjEj-LqystVLKbSTQYcdTJT9X2m-W3ovVzc8l18m-g9PSvQnU71bw3hdffI= xZUEcsF3PsOVn41GoTZFOwc$ for graphic product... ATTN...WFO...FWD...LUB...MAF...OUN...SHV...SJT...TSA... ATTN...RFC...ABRFC...LMRFC...WGRFC...NWC... LAT...LON 34569533 34149464 33269481 33109708 32719926=20 32770107 33849973 34499717=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) .