Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sun May 04 2025 18:34:33 AWUS01 KWNH 041834 FFGMPD TXZ000-NMZ000-050030- Mesoscale Precipitation Discussion 0217 NWS Weather Prediction Center College Park MD 233 PM EDT Sun May 04 2025 Areas affected...southeast and central NM and adjacent portions of TX Concerning...Heavy rainfall...Flash flooding possible Valid 041830Z - 050030Z Summary...Increasing shower and thunderstorm coverage will likely result in localized rainfall rates of 1-2"/hr with 3-6 hour totals up to 2-3". Isolated instances of flash flooding are possible. Discussion...A deep layer (700-200 mb) closed low is very slowly shifting southeastward over Southern CA, southwestern AZ, and far northwestern Mexico. An associated phased jet streak (~110 kts @ 200 mb) is progged to shift rapidly northeastward into southwest NM over the next several hours in association with DPVA from the aforementioned closed low, providing ample lift via divergence and diffluence within the idealized left-exit region of the jet streak over portions of southwestern NM by 21z. Additionally, an impressive pool of instability (SBCAPE of 1000-2500 J/kg) has built to the south over the past several hours, centered over far West TX (though 500-1000 J/kg has already built farther north as well). PWATs are a bit less impressive, ranging from 0.5-0.8" (still well below the typical PWAT during the height of the monsoon season, though highly anomalous for early May as indicated by ELP sounding climatology around the 90th perentile), though modest low-level moisture transport (via 20-25 kt LLJ @ 925-850 mb) could bring PWATs to as high as 1.0" (near record daily values at ELP). Hi-res CAMs are in good agreement concerning the development of convection this afternoon, and some deeper convective cells are already starting to develop prior to 18z. Given the presence of equally anomalous effective bulk shear (30-40 kts, near the 90th percentile), convection is expected to become organized into discrete and semi-discrete clusters with localized rainfall rates expected to reach 1-2"/hr (particularly with any supercells that develop). Storm motions near 20 kts should generally limit residence time over any one location, though limited backbuilding (particularly just north and downwind of the Sacramento Mountains where convergence is locally enhanced from differential heating) may result in localized 3-6 hour totals of 2-3". These expected isolated totals are near the associated FFGs (at 1, 3, and 6 hour intervals), and sub-hourly (15-min) totals as high as 0.50-0.75" (as indicated by the HRRR) may also drive a localized flash flood threat with the limited infiltration ability of dry desert soils. Isolated instances of flash flooding are possible, particularly in sensitive or low-lying areas (such as burn scars and dry washes). Churchill ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!_96BeVrpUQgP00lQgyqFLiW0XBUkP_rVpXQxloVljj3MsYXTZp3VkJt4x7DPo3uaH0UY= dk5ROzugEYwaHl-qS8sDaxU$ for graphic product... ATTN...WFO...ABQ...EPZ...LUB...MAF... ATTN...RFC...ABRFC...WGRFC...NWC... LAT...LON 36330501 36210418 35490367 35130330 34390300=20 33670286 32470277 31580311 31590475 32520548=20 33100610 33780693 35500690 36200635=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) .