Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sat May 27 2023 20:03:05 AWUS01 KWNH 272002 FFGMPD TXZ000-NMZ000-280200- Mesoscale Precipitation Discussion 0357 NWS Weather Prediction Center College Park MD 402 PM EDT Sat May 27 2023 Areas affected...Texas Western Panhandle...Ext Southern NM... Concerning...Heavy rainfall...Flash flooding possible Valid 272000Z - 280200Z SUMMARY...Initially intense downdrafts with 1-1.5" totals pose local flash flooding risk, but has line of cells reaches deeper moisture further east (23/00z) rainfall intensity and rates will increase further with 1.5"/15 minutes possible across less permeable soils posing flash flooding risk through early overnight period.=20 DISCUSSION...GOES-visible imagery depicts a broad line of thunderstorms across the western TX panhandle from Guadalupe Pass toward into northeast Chihuahua. CIRA LPW analysis denotes the nose of an enhanced 700-500mb moisture plume from the subtropical Pacific is starting to overlap return low level moisture flow up through the Rio Grande Valley into the Chihuahuan Plateau with Tds in the 40s to low 50s. Deeper surface/boundary layer moisture resides further east generally along 104W; however, mild diffluence in the upper-jet pattern across the region to the west of the larger scale ridge axis, is providing sufficient broad scale ascent to develop these cells. Low level easterly surface response appears to be developing stronger updrafts along favorable terrain/convergence points. The maturing phase has been quick, but initial updrafts have been slow to move off their development convergence points allowing for some highly focused torrential downpours, potentially up to 1-1.5" in the cores/along with some hail generation, this may trigger a few flash flooding concerns in the short-term.=20 However, cold pool generation and increasing steering flow aloft will dislodge the updrafts for a fairly progressive eastward propagation over the next few hours. Rainfall efficiency will be limited while ingesting these lower dew point but still unstable air to help generate a linear complex over the next few hours. As the complex reaches the deeper moisture along and east of 104W in the 23-00z time frame (though some uncertainty remains in said timing, due to storm scale strength of propagation), ingest of mid 50s to low 60s Tds as well as western edge of .5-.75" Sfc to 850mb LPW, will increase moisture flux convergence and rainfall production. Cell motions should continue to be fast, but HRRR solutions and moisture convergence values suggest 1.25-1.5" in 15 minutes is likely with spots of 2-3" particularly from the Davis Mountains southward, in the deeper low level moisture. In addition, stronger convergence on the Davis Mountains may allow for pre-cursory, slow moving development that may pre-condition local streams/creeks for enhanced stream flow/flooding as the main line passes. As such, flash flooding is considered possible throughout the evening into the early overnight period, though more likely east and after 00z. Gallina ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!6bt8iX_mvGlnqyRlq-nuIIpMmwGjXZ6jCSnBl1oFMtjDEFB5I_fPgq9CwthSfT_o99Ui= dkYLFQXsSltZHmwgSJ7JQp8$ for graphic product... ATTN...WFO...EPZ...MAF... ATTN...RFC...WGRFC...NWC... LAT...LON 32260492 32130402 31590326 31240297 30260264=20 29650265 29200283 28930310 28980346 29110360=20 29250397 29480436 29740466 30110479 30430498=20 30710526 30930553 31320561 31740527=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) .