
MD 2097 CONCERNING SEVERE POTENTIAL…WATCH UNLIKELY FOR PORTIONS OF SOUTHEASTERN CALIFORNIA…SOUTHWESTERN ARIZONA…SOUTHERN NEVADA
Mesoscale Discussion 2097 NWS Storm Prediction Center Norman OK 0148 PM CDT Thu Sep 18 2025 Areas affected...portions of southeastern California...southwestern Arizona...southern Nevada Concerning...Severe potential...Watch unlikely Valid 181848Z - 182115Z Probability of Watch Issuance...20 percent SUMMARY...A few stronger thunderstorms may produce localized damaging wind and small hail this afternoon. DISCUSSION...An extremely unseasonably moist air mass is in place across portions of southern California into southern Arizona as the remnants of tropical cyclone Mario continue to move inland. Dew points are in the mid 60s to 70s across the California and Arizona low deserts (with a dew point of 76 F noted in the observation from Yuma, AZ). A morning band of convection continues northward across southern Nevada, with some increase in intensity over the last hour owing to daytime heating, with around 1000-1500 J/kg MLCAPE noted in surface objective analysis from the RAP. Additional activity has begun to develop south of this wave across the Mexico border and into southern Arizona/California. In addition to the unseasonably moist air mass, at least some weak shear for organization (25-30 kts) is present across the deserts. This will support potential for a few stronger storms and transient supercell structures with potential for damaging wind and small hail. Overall, this risk appears to be fairly localized and as such a watch is unlikely. ..Thornton/Guyer.. 09/18/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...TWC...FGZ...PSR...VEF...SGX... LAT...LON 31871311 32831269 33521263 33841269 34081274 34441289 34701304 35361361 35411374 35541400 35591423 35581503 35521563 35451604 35301639 35071662 34841658 34481652 34301649 34081645 33841639 33561633 33331627 33151623 32851615 32641612 32541604 32501599 32501599 31871311 MOST PROBABLE PEAK WIND GUST...UP TO 60 MPH