Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Tue Jul 22 2025 18:23:52 AWUS01 KWNH 221823 FFGMPD NMZ000-AZZ000-230000- Mesoscale Precipitation Discussion 0777 NWS Weather Prediction Center College Park MD 223 PM EDT Tue Jul 22 2025 Areas affected...Southeast Arizona, Southwest New Mexico Concerning...Heavy rainfall...Flash flooding possible Valid 221822Z - 230000Z Summary...Showers and thunderstorms will continue to bubble and expand across Arizona and New Mexico into this evening. Rainfall rates will likely eclipse 1"/hr at times, leading to 1-2" of rainfall with locally higher amounts possible. This may cause flash flooding. Discussion...Satellite imagery across the Southwest this afternoon is quite revealing to the evolving flash flood risk. The GOES-E visible imagery indicates that morning cloud cover has mostly dissipated, especially south of the Mogollon Rim in AZ and Mogollon Mountains in NM. Within this clearing, Cu is rapidly bubbling thanks to the rapid destabilization, and Cb have already developed as noted in the GOES-E day-cloud microphysics RGB over southeast AZ. Additionally, an MCV is visible lifting northward from Chihuahua, and this will shift into New Mexico during the next few hours. The combination of this MCV with the RRQ of a jet streak pivoting northward towards the Four Corners acting upon the destabilizing column will drive significant ascent through the aftn. During the next few hours, the CAMs, including the HRRR, 3kmNAM, ARW2, and the HRRR forced UA-WRF are all in agreement that convection will expand and intensify. This will be in response to the aforementioned ascent, but especially due to the intense thermodynamic plume positioned across the region. Recent SPC RAP analysis indicates a corridor of PWs exceeding 1.4 inches, or above the 90th percentile for the date, collocated with a ribbon of 2000 J/kg SBCAPE centered over southeast AZ, and this SBCAPE is progged to reach above 3000 J/kg later today. The convective response to this favorable environment has already been radar-estimated rain rates of 1"/hr from KEMX, and the HREF neighborhood probabilities for 1"/hr rates increase to 40-50% by this evening. Additionally, the UA-WRF and 15-min HRRR indicate brief rates of 1.5-2"/hr likely as well. Although bulk shear will remain minimal, indicating that storms will remain of the pulse variety with limited organization, as the coverage of storms increases, mergers and interactions may occur. At the same time, as storms likely repeatedly develop into the intense thermodynamics a few locations could receive multiple rounds of storms, with the highest confidence for this across southeast AZ and into the south facing terrain of western NM. With storm motions likely remaining just 5 kts, the resulting slow motion combined with potential repeating rounds of cells could cause 1-2" of rain with local amounts potentially up to 3" (HREF 10-20% chance). 1-hr and 3-hr FFG are only around 1-1.5" due to the sensitive soils in this area and recent heavy rainfall (7-day rainfall more than 400% of normal according to AHPS). Any of these slow moving or repeating storms across these soils could cause flash flooding, although the most likely impacts would be across burn scars or urban areas. Weiss ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!9c0q4loExBz3QsGmsYS6jumcMnXL1gUgSk0mQ6gpfHYXq47w3Knx_ueyM8eWNMioL0a8= AP8z-veaxJnyvQHgAoyzTTU$ for graphic product... ATTN...WFO...ABQ...EPZ...FGZ...PSR...TWC... ATTN...RFC...FWR...STR...NWC... LAT...LON 34520917 34150804 33600717 32830681 31950671=20 31270726 31090848 31060988 31051017 31251077=20 31591122 32061138 32821134 33501118 34091092=20 34501038=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) .