Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Wed May 01 2024 23:44:32 AWUS01 KWNH 012344 FFGMPD TXZ000-OKZ000-020540- Mesoscale Precipitation Discussion 0205 NWS Weather Prediction Center College Park MD 742 PM EDT Wed May 01 2024 Areas affected...Central TX...southwest OK Concerning...Heavy rainfall...Flash flooding possible Valid 012340Z - 020540Z Summary...Localized short-term totals of 3-5" may occur with training of convection along the dry line. Isolated to scattered instances of flash flooding are possible. Discussion...Severe thunderstorms have erupted late this afternoon across central TX, along and ahead of a dry line that is bisecting the state. A favorable mesoscale environment is in place for convection and heavy rainfall to persist, including an ML CAPE gradient of 1500-3500 J/kg, PWATs of 0.8-1.2 inches (near the 90th percentile, per surrounding SPC sounding climatogology), and effective bulk shear of 25-45 kts (provided by left exit region of a modest subtropical jet streak). Deep convective cells have been capable of 2-3"/hr rainfall rates per MRMS, and locally hourly estimates have also approached this range (2-3") as steering flow being oriented towards the NE parallels a good portion of the dry line. This is allowing the cells that are filling-in along the line to train/repeat, which can very quickly result in locally significant flash flooding. Given that expectation, it's not too surprising to see some of the latest HRRR runs indicating localized 3-5" totals through 06z near the TX/OK Red River border region (though overall the model is still too timid with convective development, given trends). While much of the 12z CAM guidance is not particularly organized (or helpful) with the depiction of the convection, there are still some appreciably high probabilities (~25%) for localized 3" exceedance through 06z, per a 40-km neighborhood via the 12z HREF suite. Isolated to scattered instances of flash flooding are considered to be possible. Churchill ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!62RvKhH8XDxWDO_L6iEfpiHAiHYjgjKB2J3SqoGHCm7mq_hSKcX4_QuV_4N491N0l9C7= TLXH7vVbv66n3CaAhVBv-K4$ for graphic product... ATTN...WFO...AMA...FWD...LUB...MAF...OUN...SJT... ATTN...RFC...ABRFC...WGRFC...NWC... LAT...LON 35499969 34969785 34529767 33609789 32739820=20 32299970 32380196 33100237 33850175 34800114=20 35190055=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) .