SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1206 PM CDT Tue Sep 30 2025 Valid 011200Z - 021200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... The risk for severe thunderstorms appears negligible on Wednesday. ...Synopsis and Discussion... An upper trough will remain over the northwestern states on Wednesday as an upper low slowly fills off the coast of British Columbia. Cool temperatures aloft combined with daytime heating may yield isolated weak thunderstorms across coastal WA and perhaps over northern ID and vicinity. To the east, southwest flow aloft and a lead wave will affect the northern Plains, where a surface trough and wind shift will develop. Weak instability, some elevated, combined with a developing southerly low-level jet may support isolated thunderstorms late afternoon through evening, with little if any severe potential. Elsewhere, an area of cooler air aloft will move from the Gulf eastward across FL late Wednesday night, which when combined with increasing shoreline convergence along the eastern shores of the FL Peninsula could yield a few thunderstorms as a harsh midlevel subsidence inversion is gradually reduced. For the daytime period, little if any lightning is anticipated due to the inversion, though shallow convective showers will still be possible. ..Jewell.. 09/30/2025
