Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Wed Oct 25 2023 04:33:32 AWUS01 KWNH 250433 FFGMPD TXZ000-251000- Mesoscale Precipitation Discussion 1154 NWS Weather Prediction Center College Park MD 1232 AM EDT Wed Oct 25 2023 Areas affected...Cap Rock, Permian Basin and Eastern Trans-Pecos Region of Western Texas... Concerning...Heavy rainfall...Flash flooding possible Valid 250430Z - 251000Z SUMMARY...Eastward progressing squall line will intersect deeper moisture from the Western Gulf and increase sub-hourly rates to over 1" with potential of spots of 2"/hr as the line passes. Hard ground conditions and lower hourly FFG further east will also increase potential for spotty incidents of flash flooding through early morning. DISCUSSION...Regional RADAR mosaic and GOES-E 10.3um EIR loop shows increasing convective activity along the length of the leading edge of larger scale height-falls associated with the slow advancement of the 1.5-2 standard deviation closed low over NW Old Mexico. Forward propagation of the line will be a limiting factor for total rainfall especially over the next hour or so as the convective line matures and a mix of mid-level dry air supports cold pool generation and some QLCS bowing segments within the line. However, strong southeasterly surface to boundary layer flow is sliding through the Rio Grande and Pecos river valleys with 20-25kts of flux which is accompanied with Tds into the upper 60s. CIRA LPW shows this slug is deeper a bit upstream near the intersection of those Rivers with SFC-850mb PW values over .75 nearing 1". Which should provide ample moisture flux to support intense rainfall rates. While the other layers (850-500mb) remain further east generally responding to the exiting sub-tropical shear axis/remnants of Norma leaving into the Central Plains, the reservoir will be available toward the end of the valid time of this MPD as Total PWat get into the 1.5-1.7" range by 09z over the Lower Pecos toward eastern Permian Basin. Given the convergence and modest lapse rates aloft, the stronger thunderstorms will support solid moisture loading and support sub-hourly totals of 1-2" with HRRR 15-min rain totals suggesting ..75-1" values with the initial cores, with duration of 15-45 minutes possible. Hourly FFG values are generally between 1.5-2" east of 102W from Hale to Terrell county. As such, flash flooding is considered possible. There is a sub-mesoscale concern for localized higher totals due to dry air entrainment/cold pool generation along the N-S line.=20 Small bowing segments may allow for weak waves along the squall line, increasing duration of intense rates. While the duration is not likely to be significantly longer, an additional 15-30 minutes of these intense bursts may allow for highly localized totals up to 2-2.5" resulting in the more probable result of localized flash flooding. Currently, one of these segments appears to be occurring near Andrews/Gaines county line, though others may occur.=20=20 Gallina ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!7JBkSVaayh8zCjC-9p_JmZnM_lWJJIkoMP6b3Zu9MjThf-bvtV2jV-6aZOzmCqrFU4cz= 4REZ9g7AFcHX3KBnEuRWf-w$ for graphic product... ATTN...WFO...EWX...LUB...MAF...SJT... ATTN...RFC...ABRFC...WGRFC...NWC... LAT...LON 34450131 33940028 33080003 32360020 31010087=20 30480100 29580152 29710222 29250275 28940313=20 29070369 29740382 31030361 31980305 33000268=20 34090235 34420188=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) .