A low latitude cutoff low-pressure system west-northwest of Hawaii entrained tropical moisture during the past week causing heavy thunderstorms across Hawaii and the attendant latent heat release amplified the downstream upper ridge pattern which is bringing record warmth to the West U.S. To compensate for the upper ridge, a deep trough formed in the East-central U.S. early this week causing a widespread severe weather outbreak.

A squall line has (temporarily) lost severe weather qualifiers moving east across the east/southeast Ohio Valley this morning while the southern end of the squall line maintains tornado risk for Mississippi and Alabama. Later today, the squall line re-energizes and brings severe storms including a large tornado risk area to the East.

Major severe weather outbreaks are forecast for today and tomorrow across the eastern third of the U.S. Today’s outbreak includes the East-central and Southeast U.S. Tornado risk is widespread and most focused on the Central Mississippi River Valley. On Monday, the severe weather event regenerates on the U.S. East Coast and features widespread high wind damage risk including tornado threat from South Carolina to Pennsylvania.

U.S. meteorological winter 2025-26 was the warmest on record for 9 western U.S. states from Oregon to Texas. The western half of the U.S. finished MUCH ABOVE or RECORD warm. The only colder than normal states were Ohio, Pennsylvania, Maryland, Delaware, New Jersey, New York, and Massachusetts. Delaware was the coldest state (historically). U.S. county temperature rankings reveal much of the Southwest U.S. including the southern half of California were record warm during 2025-26 meteorological winter. Much of the Northeast U.S. Corridor was marginally colder than normal during the winter season.