Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Mon May 19 2025 21:59:14 AWUS01 KWNH 192157 FFGMPD MOZ000-ARZ000-TXZ000-OKZ000-KSZ000-200200- Mesoscale Precipitation Discussion 0290 NWS Weather Prediction Center College Park MD 556 PM EDT Mon May 19 2025 Areas affected...far North TX into much of central and eastern OK, adjacent portions of far northwest AR, southwest MO, southeast KS Concerning...Heavy rainfall...Flash flooding likely Valid 192155Z - 200200Z Summary...Hourly rainfall as high as 2-3" to result in additional localized 3-6" through 02z (9pm CDT). Scattered instances of flash flooding are likely (and may be locally significant). Discussion...Discrete clusters of supercells are gradually becoming more prolific across far North TX into much of central and eastern OK, within a mesoscale environment characterized by SBCAPE of 2500-5000 J/kg, PWATs of 1.6-2.0 inches (near or exceeding the daily max value, per OUN/SGF sounding climatology), and deep layer (0-6 km) shear of 55-65 kts (above the 90th percentile). While storm motions are generally fast in this environment (with both the deep layer mean flow and bunkers right vectors 45-55 kts towards the NNE-NE), storms are increasingly organizing linearly with localized training of cells already resulting in some 2-3" totals (with MRMS and some local observations starting to indicate these totals in as little as an hour). As convection continues to organize with the approach of a potent shortwave trough over the TX Panhandle, expect convection to continue to proliferate and grow upscale with already substantial divergence aloft only further increasing (as the MPD region is within a very favorable placement between semi-phased subtropical and polar jet streaks). This may eventually result in somewhat slower (20-30 kt) storm motions more generally towards the east as convection begins to propagate upwind (towards the low-level jet, per the Corfidi vectors). Until convection organizes more linearly with meaningful eastward propagation, expect storms to continue to increase in coverage and result in additional localized training elements with additional localized totals as high as 3-6" possible (per hourly HRRR and experimental RRFS output, which has corrected westward in recent runs relative to the 12z HREF and 00z RRFS suites). Experimental WoFS 90th percentile of accumulated rainfall also agrees with this potential (and even indicates the potential for isolated 6"+ totals north of the DFW metro area in far North TX with backbuilding towards the dryline with unimpeded strong low-level inflow from the Gulf). Scattered instances of flash flooding are likely (and may be locally significant, especially if 6"+ totals occur over sensitive localities that have seen as much as 2-3" of rain over the past 3-24 hours). Churchill ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!59xDXd0SdSLI66eX_ARHnkHbV6RnZ4_HBJT9Y53aSEJp8Rhvy0pI1S--IA_0HcA9d4--= JCfcn5uqDK4XuhpkzzUzA7Y$ for graphic product... ATTN...WFO...FWD...ICT...LZK...OUN...SGF...SHV...TSA... ATTN...RFC...ABRFC...LMRFC...WGRFC...NWC... LAT...LON 37279552 36909358 35889340 34449471 33559584=20 32919792 33419840 35279669 36669617=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) .