Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sun Oct 12 2025 08:12:16 AWUS01 KWNH 120812 FFGMPD AZZ000-121411- Mesoscale Precipitation Discussion 1185 NWS Weather Prediction Center College Park MD 411 AM EDT Sun Oct 12 2025 Areas affected...southern/central Arizona Concerning...Heavy rainfall...Flash flooding likely Valid 120811Z - 121411Z Summary...Showers and isolated thunderstorms will continue to increase in coverage through at least 13Z/7a MST this morning.=20 Areas of flash flooding are expected during that timeframe. Discussion...Larger-scale ascent was beginning to overspread much of the Southwest due to a stout mid-level wave centered over Nevada and northwestern Utah. Meanwhile, a pool of 1000 J/kg SBCAPE and weak inhibition has supported development of scattered thunderstorms from the Phoenix area east to near Globe. The storms are embedded in a moist airmass (1.1-1.5 inch PW values), supporting rain rates at or above 1 inch/hr in the strongest cells. Relatively quick movement has been noted owing to 40 knots of mean steering flow. However, as cells continue to expand in coverage and intensity, local mergers and backbuilding should also bump rain rates to above 1 inch/hr at times. The flash flood risk will increase as a result. Models/CAMs suggest that the greatest concentration of thunderstorm activity will reside along and just south of the Mogollon Rim through 13Z/7a MST this morning. This includes the Phoenix Metro area. Much of the discussion area remains well ahead of any low-level boundaries that could stabilize this airmass, and with continued ascent/height falls over the region, flash flood potential will likely extend beyond 13Z/7a MST. Both urban and sensitive/low-lying areas will have the greatest flash flood risk. Cook ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!5KHFFKLCfKHP79HS4HKsVvL2N0a3s-xJb_9m1OwSChAQUXuANbCvsiVKZ0v7LtkRGvIq= u6ucjJEG3YhQQhL9CEz7PrU$ for graphic product... ATTN...WFO...FGZ...PSR...TWC... ATTN...RFC...STR...NWC... LAT...LON 34471072 34050941 32830932 31381045 31801316=20 32601435 33471431 33951357 34201246=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) .