SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1210 PM CDT Mon Sep 29 2025 Valid 301200Z - 011200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe storms appear unlikely on Tuesday. ...Synopsis and Discussion... A deep upper low will exist off the coast of British Columbia, with a large area of cyclonic flow aloft encompassing much of the western states. Cooling aloft with a leading wave as well as daytime heating will lead to scattered thunderstorms over parts of the Great Basin into MT, but with relatively weak instability. To the east, an upper ridge will exist from the MS Valley into the upper Great Lakes, with an upper trough from New England into the Maritimes. Midlevel moisture over the Southeast as well cool temperatures aloft could yield isolated thunderstorms over the southern Appalachians during the afternoon, while daytime heating and coastal convergence within a moist air mass support a few cells developing over eastern/southeastern coasts of the FL Peninsula. Elsewhere, a surface trough will develop over the northern High Plains, with instability developing from northern MN into ND. Thunderstorms chances are generally low in these areas due to weak ascent, but a storm or two cannot be ruled out near peak heating. ..Jewell.. 09/29/2025
