Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sun Nov 03 2024 19:56:28 AWUS01 KWNH 031956 FFGMPD TXZ000-OKZ000-040200- Mesoscale Precipitation Discussion 1118 NWS Weather Prediction Center College Park MD 255 PM EST Sun Nov 03 2024 Areas affected...central and southern OK...North TX Concerning...Heavy rainfall...Flash flooding likely Valid 032000Z - 040200Z Summary...Localized 2-4" short term totals likely to result in isolated to scattered instances of flash flooding through the afternoon. Discussion...Convective coverage is increasing this afternoon across North TX and southern OK, the most intense of which initiated in the vicinity of the dry line this morning (and is quickly organizing into a distinct bow echo). This region is encompassed within a large warm sector and associated low-level convergence, and instability is once again building after the passage of an organized MCS overnight. The mesoscale environment is characterized by ML CAPE of 1000-2000 J/kg (except over northeast OK, though continued warm air advection and isentropic lift will change that over the next several hours), PWATs of 1.4-1.7 inches (near record levels, per OUN sounding climatology), and effective bulk shear of 45-55 kts. Continued building instability within this favorable environment will support increased coverage and intensity of convection into the evening. This is especially the case given the upper-level support, as upper-level diffluence is even more impressive than the low-level convergence (with a phased northern and southern stream allowing for idealized left-exit region of a sub-tropical jet streak and right-entrance region of a polar jet streak). Given the prior rainfall over the past 24 hours (locally up to 3-6"+ over much of OK, per MRMS estimates), antecedent conditions will be more supportive of excessive rainfall with this next round of storms. Hi-res CAMs are in relatively good agreement with convective evolution, suggesting the potential for localized 2-4" totals over the next 3-6 hours (per HREF probability-matched mean QPF). While fast storm motions should generally limit hourly totals to 1.5" or so (at least through 02z), localized repeating/training of these rates should support those advertised 3-6 hour totals. The corresponding Flash Flood Guidance (FFG) are on the order of only 1.5-3.0" (given the aforementioned antecedent conditions), so isolated to scattered instances of flash flooding are considered likely. Churchill ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!9GoAKxlm-gjyqehAGTrt7i73DGblpUjZlVoVP1BmPCr1TKxp0RuyDh2p2TxivO--G7yp= S_OTBIUEhW8e9zT53YjaygU$ for graphic product... ATTN...WFO...FWD...OUN...SJT...TSA... ATTN...RFC...ABRFC...WGRFC...NWC... LAT...LON 36849700 36489552 34709566 33309664 32669743=20 32449864 32149960 32259996 33489973 34559997=20 35109963 35689850=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) .