Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Thu Mar 21 2024 21:09:49 AWUS01 KWNH 212109 FFGMPD TXZ000-OKZ000-220245- Mesoscale Precipitation Discussion 0106 NWS Weather Prediction Center College Park MD 508 PM EDT Thu Mar 21 2024 Areas affected...Southern Oklahoma to Northern Texas Concerning...Heavy rainfall...Flash flooding possible Valid 212107Z - 220245Z Summary...Isolated flash flooding is possible across portions of southern Oklahoma into northern Texas as a shortwave trough moves eastward near the Red River and convection begins to grow upscale in coverage and intensity this afternoon. Localized rainfall totals of 2 to 4 inches remains possible where cell motions are reduced close to the ejecting trough/low. Discussion...Radar showed convection beginning to grow either side of the Red River in proximity in the vicinity of a pair of shortwave troughs, a weak dryline in the area, and a quasi-stationary front located to the north.=20 The HRRR runs from late this morning and this afternoon have been showing run to run differences in placement of the heaviest rainfall...but a consistent theme has been for the axis of heaviest rain to be along and immediately south of the track of the trough where greater surface-based instability should result from better daytime heating/steeper low/mid level lapse rates.=20 Surface flow is fairly weak into the region and 850 mb flow is modest...15 to 20 kts at best as shown by latest VWPs from the Gulf coast region northward into central/eastern Texas...but the flow was favoring moisture transport ahead of the trough/low.=20 Flash flood guidance was generally at or above 2.5 inches per hour and closer to 3 inches per 3 hours hour across MPD area. Thinking is that localized maximum rainfall amounts of 2 to 4 inches are possible should the cells slow down in response to the approach of the upper system...so instances of flash flooding rainfall may occur but should be isolated in coverage. Bann ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!6_FeLZE96OSnJlNZ2973vjkdbAAp9m9k-uqPX_VS1D3Ae3mFp4rxfRaYQSvL8inTH4Hy= X2KURYPgg67fRQMGZBiDj60$ for graphic product... ATTN...WFO...FWD...OUN...SJT... ATTN...RFC...ABRFC...WGRFC...NWC... LAT...LON 34559881 34469786 34129710 33559663 33179667=20 32769690 31929791 31349894 31300006 31920005=20 32909947 33469953 34319984=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) .