WEATHERAmerica Newsletter, Sunday, December 7, 2025; NEXT TEN DAYS

[Larry Cosgrove]

SHORT RANGE OUTLOOK

(Through The Next 72 Hours)

 

Another Cold 500MB Vortex Moves Through The Great Lakes And Northeast!

METEOBLUE

Pivotal Weather (3)

ECMWF

College Of DuPage Weather Laboratory (2)

Warmer air is slowly gaining ground across the western and southern tiers of the nation. That said, cold with upper lows and snow squalls still dominate the northern tier, and will hold through the new week. A breakaway disturbance from off of California may enhance drizzle and rainfall along the Gulf Coast. Snow squalls will be numerous through southern Canada and the Great Lakes region, with the Arctic air mass tending to deepen through Alberta and Saskatchewan. The Gulf of Alaska vortex should have a broad and intense impact in British Columbia, Washington and Oregon, but dry somewhat crossing the Rocky Mountains into the Prairie Provinces.

 

MEDIUM RANGE OUTLOOK

(Four To Ten Days From Now)

Warm-Up Spreads East Before A Major Arctic Intrusion From Canada

METEOBLUE

WeatherBELL (4)

ECMWF (4)

College Of DuPage Weather Laboratory (2)

With the Holiday Season fast approaching, there needs to be ample warning time for major cold and frozen precipitation potential. The numerical models have gone back and forth on these weather types (on Saturday, major cold gave way to record warmth...), so it makes sense to follow those schemes which have been most steady/consistent. That means the GFS, GEM, and the CFSoutlines, which imply a cold solution mostly after December 21 east of the Rocky Mountains. But a strong warm-up may reach the edge of the snowpack, which in this case appears to be very near Interstate 80 in the medium range. An upper low may linger in Ontario and Quebec, so my thinking is that the Great Lakes, New England and mid-Atlantic may stay fairly chilly while the warmth concentrates in the south central and Gulf Coast states. I suspect that a storm now off of the Baja California coast will be a catalyst for change to cold air drainage at the end of this period.