WEATHERAmerica Newsletter, Sunday, March 1, 2026: EXTENDED PERIOD FORECAST

[Larry Cosgrove]

EXTENDED PERIOD FORECAST

(Between Day 11 And Day 15)

 

One Last Gasp Of Winter Weather From The Rocky Mountains To The Upper Mississippi Valley?

NOHRSC (2)

CIMSS (2)

TropicalTidbits.Com (3) (Dr. Levi Cowan)

NOAA/PMEL

NOAA/CPC

HPRCC/University Of Nebraska (2)

Environment Canada

WeatherBELL (9)

Seeing a building connection from the Madden-Julian Oscillation to a vortex below the Aleutian Islands might normally be cause to forecast a major Arctic intrusion through the eastern two-thirds of North America. Problem is, the gyre is progressive, the sun angle is getting higher (which minimizes snow cover and air mass chill duration) and the storm track often takes a higher-latitude route. I read some comments about "stratospheric warming to the rescue of winter weather", but remind everyone that the impact of the SSW events is 2 to 4 weeks ahead of occurrence and that impacts for cold generation and downstream amplification are often unreliable after Valentine's Day, and are more or less worthless after St. Patrick's Days. You may want big snows and Arctic intrusions to return, however the high impact scenarios of 1962 and 1993 are very hard to attain in an era where lasting-duration temperature drops and genuine blizzards are increasingly rare.

Which is not to say that winter is done yet. At least, not entirely. The first piece of energy coming out of the Gulf of Alaska will migrate eastward, just below the Canadian border, over the following five days. This path should bring a bitter cold Canada vs. milder USA set-up in the near term and medium range, with the Arctic regime making gains in the Desert and Intermountain Regions (temporarily, with a full-latitude 500MB trough reaching into Baja California). On the idea that the ECMWF series is a day too slow with ejection of the disturbed area, we should see cyclogenesis near Lamar CO around March 9 with the storm slowing, becoming vertically stacked, and moving in the general direction of Minneapolis MN. A closed system like this might put down a lot of snow, generate a great deal of wind in the Front Range (CO/WY) and very heavy snow from the High Plains into the Black Hills SD into the Red River Valley (MN/ND). Left behind energy could create a window for a convective situation from TX and OK into the Ohio and Tennessee Valleys at some point between March 12 -15. The cold air drainage may be impressive in the Great Plains and Mississippi Valley, but most of the model guidance and analogs revert back to that "cold Canada vs. warm USA) set-up through the rest of the month, similar to what the CanSIPS and CFS panels show for March mean surface temperature.

I will post the DJF averages on Tuesday. Note that in February, a sharp warmer than normal West/Central vs. cold East alignment occurred, with normal to below average precipitation amounts dominant nationally. Curiously, the greatest moisture impact from snow was in the far north central states. The major storm impact from last weekend was surprisingly minimal, this despite high amounts ranging between 20 and 40 inches with blizzard conditions. The dryness in the West, Great Plains and Texas could be an important player as we move closer to summer.

 

.Prepared by Meteorologist LARRY COSGROVE on 
Sunday, March 1, 2026 at 1:40 A.M. CT

Disclaimer: 
The previous statements are my opinions only, and should not be construed as definitive fact. Links provided on this newsletter are not affiliated with WEATHERAmerica and the publisher is not responsible for content posted or associated with those sites.

Copyright 2026 by Larry Cosgrove

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