WEATHERAmerica Newsletter, Sunday, October 5, 2025; EXTENDED PERIOD FORECAST

[Larry Cosgrove]

EXTENDED PERIOD FORECAST

(Between Day 11 And Day 15)

 

Trying To Figure Out If And When The Next Polar Air Mass Will Take Control

CIMSS (3)

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

NOAA/PMEL

NOAA/CPC

HPRCC/University Of Nebraska (2)

Environment Canada

WeatherBell (8)

There are still quite a few elements of autumn in the forecast. For that reason, it would be unwise to even attempt a season DJFM outlook. Even if many of these outlooks are appearing on the Internet. There is no "magic bullet", such as an index or major weather event, that can tell you, the reader, how to prepare for the holiday season, snow/ice removal, or travel. You must wait until the first half of October data is in (usually around October 17), and by that date to look at snowfall in Eurasia and North America. One interesting aside that I will use: number of named tropical storms in each theater, most importantly the Pacific Basin vs. those in the Atlantic Basin, as a possible analog, since the pattern of systems this year has been going against ENSO climatology.

While cold fronts have passed through the continent with some regularity in late summer and early fall, so far the temperature drops have been in the cP or cPk range. Each injection of lower readings has been relatively brief, with not a hint of Arctic readings in Canada to derive from. Consider that the giant sub-Aleutian and Gulf of Alaska gyres are bound to dig to lower latitudes. I keep seeing blocking signatures arise in the -EPO, +PNA, -AO, and -NAO positions. At some point this month truly cold values will be introduced to the lower 48 states. I am inclined to think that a tropical cyclone will be the catalyst for change, either along the Gulf Coast or the Eastern Seaboard. or perhaps somewhere in between. There is some faint resemblance to the 1992 and 2012 upper air pattern. That means in the last two weeks of October a front + hurricane threat may emerge. What to watch out for: the West should dry out and turn very warm, while a stronger trough links with a warm-core circulation. We should also see a more active hurricane risk in the Caribbean Sea and Bay of Campeche around and after Halloween.

And should you be asking about the slow transition from La Nina to a positive/neutral ENSO in late winter and spring, well yes, that is a good sign that the recent dull winters could give way to something far more interesting. As in colder, snowier, and more ice. But exactly where is not to be determined for another two weeks. Be patient.

Prepared by Meteorologist LARRY COSGROVE on 
Sunday, October 5, 2025 at 1:50 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

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