WEATHERAmerica Newsletter, EXTENDED PERIOD FORECAST, January 25, 2025

[Larry Cosgrove]

EXTENDED PERIOD FORECAST

(Between Day 11 And Day 15)

 

Ridge In Alaska, Full-Latitude Neutral-Tilt Trough Spell Colder Changes Sooner Or Later....

CIMSS (2)

NOHRSC (2)

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

NOAA/PMEL

NOAA/CPC

IRI/Columbia University

HPRCC/University Of Nebraska (2)

Environment Canada

ECMWF (3)

TropicalTidbits.Com (Dr. Levi Cowan) (5)

NOAA/CPC

Usually, each winter I look at the relative mid-point in later January to see where things are headed before spring arrives. Mind you, I still go buy calendar marks for the change of the season, as in many MAM time frames the cold will linger, and chances for snowfall can go into April in some populated parts of the lower 48 states and southern Canada. If you have not noticed, just look back at recent years where winter did not show up until well after the turn of the New Year, and then did not stop on the Equinox. That might have something to do with climate change, or at may not. But the point here is that cold air and frozen precipitation are not always coincidental with "meteorological spring".

Our challenge now in prediction revolves around the persistent reformation of blocking ridges in Alaska.  Everytime positive 500MB height anomalies arise along the West Coast and into the northwestern corner of the continent, cAk regimes form over the North Pole and streak southward. The cold/snow event early last week was the strongest example of this pattern. I think that we are likely to see this scenario happen perhaps a couple of more times before the dryness in the West and resurgence of the Sargasso Sea/Greater Antilles takes its toll. All of the model ensemble platforms are very aggressive with a warm/hot Spring and a brutal scorcher summer. But before we get there....

1966-67 continues to provide the best ONI analog, and that winter had two critical, synoptic scale heavy snow events that affected, respectively, the Great Plains/Midwest and the Northeast. There were impressive cold intrusions, too, but gaps in between the Arctic intrusions. The ECMWF panels have generally performed the best so far this winter, and that series is showing a very strong Alaskan block in the 11-15 day period. So after a recovery, the cold and the frozen precipitation should make a comeback before we see a shift to a negative/neutral ENSO signature (now a pronounced moderate La Nina) with a very warm and dry Southwest+South Central USA. In short, we are not done with winter by any means, and I would not be surprised to see the area from North Texas to the Great Lakes and Northeast have a shot at a significant snow/ice event.

 

Prepared by Meteorologist LARRY COSGROVE on 
Saturday, January 25, 2025 at 1:05 P.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 2025 by Larry Cosgrove

All rights reserved.
This publication may not be reproduced or redistributed in whole or in part without the expressed written consent of the author.

Add reaction