The first month of my Winter Outlook for December 2025 verified very well overall with the well below normal temperatures and normal snowfall /within 5.0"/. By far the strongest signal for the beginning of winter on the analogues was a cold December. Actually; the below normal temperatures carried into December from a colder ending to November also a dominant feature in the forecast. December 2026 average of 27.7 degrees averaged -3.6 below normal. Even though a colder than average December did occur; the temperature roller coaster ride didn't disappoint either with quite a variability in temperatures. Temperatures ranged from 61 /record 64/ just occurred a few days back on the 28th late at night and 59 degrees just after midnight on the 29th (also two 53's on the 18th/23rd). On the cold side; a 5 degree low on the 5th & 6 degrees on the 14th and 7 on the 8th. All the analogue temperatures averaged 28.5 compared to the 27.7 degrees for this Decembers with 1981-82 the closest temperature-wise with only one tenth different from this December's 27.7 degrees. Snowfall was shy /11.6"/ however of the snowfall back then with 17.3".
While on snowfall; December's analogue snowfall average wasn't bad either with 9.5" projected compared to the 11.6" that fell. Season 2025-26 snowfall total is running above normal this far /+6.0"/ thru December with 16.8" of the 10.8" average falling.
Model Performance
First off the best model for 500 MB troughing and Surface temperatures thus far; CANSIPS. The model actually closely pegged for temperatures for December and matched Analogues for Southeast Mich. Precipitation projection wasn't bad either with normal to slightly below. Precipitation for December was 2.12" just a bit below the norm of 2.25".
December 500 MB 2025 /Made Dec 1 2025/
December Surface Temps Departure /Made Dec 1 2025/
December Surface Pcpn Departure /Made Dec 1 2025/
For the rest of the cold season; January Analogues and CANSIPS Model go with another below normal month for temperatures and normal month for snowfall for analogues and above precipitation for CANSIPS. I'd be surprised if temperature departures are as cold for January as the analogues averaged (colder than December) and CANSIPS. Model projection is also colder or below normal temperatures. Again, stated many times - timing of the analogue data is important. Analogues and CANSIPS agreed the first half of the winter would be most affected by more or less - sustained cold. Since late November; even with far ranging temperatures (stated above) - temperatures still averaged several degrees below normal. Even though I surmise we've seen the most sustained cold in monthly departures and still have notable cold- the bigger question is what about snow?
That was not so clear-cut in analogues nor models. It seems every time we do see a wet, strong system - it's mainly been rain. The storm track into the western Lakes (also drawn on Winter Outlook prevailing storm tracks map) has been dominant, second only to Clippers. Looking at the heavy snows and wind with these storms up north clearly shows this. The Ohio Valley storms and East Coaster have only intermittently showed face. This has a strong correlation to the dominant upper wind jets over the country from the Arctic and Pacific. A shift to the west/south for the jets and slightly further east with phasing would help bring those tracks more active (though East Coast storms have picked up a bit). We'll see....
January 500 MB Forecast /Made Dec 1 2025/
January Surface Temps Departure /Made Dec 1 2025/
More updates when deemed applicable!
