Weather across America

(NATIONAL) A Marginal Risk of severe thunderstorms over parts of the Florida Peninsula, light snow along the southern shore of Lake Superior, temperatures above average over the Southwest, and below average from the east to the Southern Plains.

A front extending across the Florida Peninsula Coast will slowly move southward of the Florida by Monday afternoon. Showers with strong to severe thunderstorms will develop along the boundary. Therefore, the SPC has issued a Marginal Risk (level 1/5) of severe thunderstorms over parts of the Florida Peninsula through Monday morning. The hazards associated with these thunderstorms are frequent lightning, severe thunderstorm wind gusts, hail, and a minimal threat of tornadoes.  

On Monday, the front moves south of Florida by afternoon. Showers with strong to severe thunderstorms will develop over parts of the Florida Peninsula until the boundary moves offshore. Therefore, the SPC has issued a Marginal Risk (level 1/5) of severe thunderstorms over parts of the Florida Peninsula through Monday afternoon. The hazards associated with these thunderstorms are frequent lightning, severe thunderstorm wind gusts, hail, and a few tornadoes. 

Meanwhile, high pressure over the Middle Mississippi Valley/Southern Plains will gradually shift eastward, reaching off the Southeast Coast by Tuesday evening. Clear skies and light wind will help allow temperatures to be 5 to 15 degrees below average from the Northeast to the Southeast and then to the Southern Plains, which will experience a slight warming trend by Tuesday afternoon. In contrast, temperatures will be 5 to 15 degrees above average over parts of the Southwest through Tuesday evening.  

A second front over the Northern Rockies to the Great Basin will also move eastward to the Great Lakes to the Southern Plains by Tuesday. On Monday, as the boundary moves onto the Plains, a weak plume of moisture flows from the Western Gulf of Mexico to the Upper Midwest, aiding in the development of rain over parts of the Northern Plains and the Upper Mississippi Valley overnight Monday into Tuesday. 

On Tuesday, the rain moves into the Great Lakes. By Tuesday evening, the rain will extend from the Lower Great Lakes southwestward to the Middle Mississippi Valley. Cold high pressure over Hudson Bay will stream cold air over Lake Superior, developing light snow over the southern shore of Lake Superior.