SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1222 AM CDT Sun Oct 12 2025 Valid 121200Z - 131200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe-storm risk appears negligible today. ...Southwestern U.S... Large-scale upper ridge is forecast to remain anchored over northeast Mexico into TX through the day1 period as a strong upper low digs south along the Pacific Northwest Coast. This flow regime will ensure modest-strong southwesterly midlevel flow will persist across much of the western U.S. Latest model guidance continues to suggest a favorably moist trajectory across northwest Mexico into AZ. Seasonally high PW air mass will hold near the international border, but forecast soundings also suggest lapse rates should remain poor - though sufficient for at least 500-1000 J/kg MLCAPE by afternoon. With minimal CINH, convective temperatures will easily be breached and isolated-scattered thunderstorms should readily develop. While a few storms may exhibit some weak rotation at times, current thinking is this environment is not particularly conducive for more than sub-marginal wind gusts with the most robust convection. ...Elsewhere... Isolated thunderstorms are expected across the upper MS Valley in advance of a strong short-wave trough, and along/near the Atlantic Coast in association with a cyclone that is lifting north, just offshore. Poor instability across these regions do not support severe thunderstorms. ..Darrow/Weinman.. 10/12/2025
