SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1200 AM CDT Mon Oct 27 2025 Valid 271200Z - 281200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... The risk for severe thunderstorms appears negligible across the U.S. today through tonight. ...Discussion... Models indicate that a blocking mid/upper high will continue to evolve northeast of the upper Great Lakes into the southern Hudson/James Bay vicinity through this period. At the same time, it appears that the westerlies emanating from the mid-latitude Pacific will undergo amplification, leading to building ridging across British Columbia and the Pacific Northwest, and digging downstream troughing across the Wyoming/Colorado Rockies into the central Great Plains. As this occurs, an initially slow moving downstream low may accelerate across the Mid South into the southern Appalachians vicinity by early Tuesday. While this evolving regime is forecast to maintain cold surface ridging across the eastern Canadian provinces through the Mid Atlantic, Ohio Valley and Great Lakes region, it appears that another notable surface ridge will build across the Intermountain West and Rockies into the Great Plains, before substantive low-level moistening occurs within modest lee surface troughing initially across the high plains. As the leading edge of cyclonic mid-level flow associated with the Southeastern low spreads across the south Atlantic coast, modest surface cyclogenesis may commence offshore as early as this afternoon. In its wake, cool/stable conditions will be reinforced across much of the Southeast through northwestern Gulf Basin. ...Florida... Beneath broadly difluent, cyclonic mid/upper flow overspreading the region, scattered thunderstorm development appears probable as a moist boundary layer destabilizes with insolation by this afternoon. Although some hail and gusty winds might accompany stronger convection, potential for reaching severe limits still seems limited due to the lack of colder air aloft, and generally modest to weak lower/mid-tropospheric wind fields/shear. ..Kerr/Wendt.. 10/27/2025
