WEATHERAmerica Newsletter, Saturday, December 13, 2025; SHORT And MEDIUM RANGE OUTLOOKS

[Larry Cosgrove]

SHORT RANGE OUTLOOK

(Through The Next 72 Hours)

 

Cold Canada/New England Vs. Warm Rest Of The USA Alignment

METEOBLUE 

PivotalWeather.Com (3)

WeatherBELL

College Of DuPage Weather Laboratory (2)

In most cases, at least two 500MB blocking signatures at the higher latitudes are required to set up an Arctic intrusion affecting the lower 48 states (especially to the right of the Continental Divide). On the other hand, should a ridge reach 588dcm, the chance for unseasonable warmth increases dramatically. For a week now, the various forecast models have emphasized a heat ridge formation in Texas and Louisiana. Occasionally a -NAO styled block is shown over Greenland or Iceland, while broad and intense Gulf of Alaska mAk vortex remains west of British Columbia. Shortwaves ejecting from the gyre cross southernmost Canada and descend into the Northeast, keeping a vast snow field and ream of bitter cold that stretches from the Pacific Northwest along the International Border through New England and the Maritime Provinces. This formula could almost guarantee a very warm southern two-thirds of the USA, while making driving a chancy proposition along and above the Interstate 94 and 96 system nearest the boundary with Canada. But warmth will reign supreme through Christmas Eve. 

I hope that Santa can deal with flying through an icebox into weather flush out of the Mexican Deserts.

MEDIUM RANGE OUTLOOK

(Four To Ten Days From Now)

Imitation Of December 2007 In Texas: Just How Warm Could The Lone Star State Get?

METEOBLUE

TrueWx.Com (4)

WeatherBell (4)

College Of DuPage Weather Laboratory (2)

When I first moved to Texas from the New York NY metro in the second week of December 2007, I was stunned to see a transition from the mid-teens to lower 90s. Never did I imagine that same scenario could reoccur. But looking at the latest forecast models (of which there are many more of these days), I continue with the set-up of the nearly extreme warmth through December 28, only to break down as a new trough takes shape across the eastern half of North America. Some of the energy will come from west of Baja California (southern branch jet stream), while another shortwave drops southeast through the Great Lakes into the Ohio and Tennessee Valleys. The expansion/retrogression of blocking into Quebec and Nunavut AR may instigate drainage of cold values from the broad snowpack in Canada and the far north of the U.S., this easing or ending near-record high temperatures before 2026 arrives.