Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Fri Sep 12 2025 19:55:22 AWUS01 KWNH 121955 FFGMPD NMZ000-AZZ000-130100- Mesoscale Precipitation Discussion 1075 NWS Weather Prediction Center College Park MD 354 PM EDT Fri Sep 12 2025 Areas affected...Southeast Arizona...Southwest New Mexico... Concerning...Heavy rainfall...Flash flooding possible Valid 121955Z - 130100Z SUMMARY...Increasing convective coverage and eventually rainfall rates. Isolated rates of 1-1.5" and scattered spots of 2" may pose localized flash flooding conditions through evening. DISCUSSION...CIRA LPW shows subtropical moisture plume from 850-500mb core along and just south of the US/Mexico border between Santa Cruz county, AZ and central Dona Ana county, NM extending northward along the AZ/NM within strong southerly confluent deep layer flow. Deep layer bulk shear, remains strong with 35-45kts mainly along the upwind edge in SE AZ as strong upper-level flow slowly approaches from the west. The base of the strong upper-level trough is also ejecting a upper-level jet streak to further support large scale ascent and divergence aloft for thunderstorms that do develop. Nearly full insolation being well south of mid to upper-level cloud coverge due to the exiting shortwave over N AZ/SE UT, has allowed temperatures to rise into the 90s across the lower valley and through the mid to upper 80s into the slightly higher topography along and south of the Mogollon Rim in SE AZ/SW NM.=20 MLCAPEs of 1500-2500 J/kg will support strong updraft developing and isobaric influenced moisture flux to any even weakly rotating updrafts. Given Tds in the 60s and the overall Total PWat values of 1.25 to 1.5", should support some localized 1-1.25"/hr totals (as instantaneous rates would be well over 2"). Deep layer flow may reduce residency at a given location, but with the upstream forcing remaining strong and slowly ejecting, should support back-building/upstream flank development to support repeating/training locally. As such, spots of 1.5-2" in 1-3 hours are likely to scattered across the area of concern. Given rugged, hard-pan soil conditions across many locations, FFG values are naturally below these hourly rates and therefore localized flash flooding conditions are considered possible through the remainder of the evening across SE AZ/SW NM. Gallina ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!4bpg3qr9z-sedWc8YUNdyNgjj0lK_zgXTenA9xgAkR5W16azxrzxt97ITFhY1_y04uC6= udddRvUAfSFZZnuMDV0uBb8$ for graphic product... ATTN...WFO...ABQ...EPZ...FGZ...PSR...TWC... ATTN...RFC...FWR...STR...NWC... LAT...LON 33900782 33220739 31900720 31700762 31630808=20 31210816 31170923 31231101 31851145 33381091=20 33801000=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 3.28-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .