That cold blast we had over the weekend was a nice jolt! The mountains got plastered white and some of the lower elevations got a small covering of snow.
Temperatures barely cracked 32*F at the ilsnow.com storm center on Sunday afternoon, which was nearly 20*F below normal for October 18th. Very impressive cold!
What’s Next?
By the time you read today’s post, this winter-like blast will quickly become a thing of the past as the cold retreats to the Canadian Maritimes and a mild zonal flow washes over the eastern United States this week:
The rapid retreat of cold is not a big deal. Cold like this does not last in October.
Siberian Snow Cover:
For October 17th, I have placed last year’s North Hemisphere snow cover anomaly map side-by-side with this year’s map:
Granted, the positive anomaly of Siberian snow cover was a bit more impressive last year. But the spread of Eurasian snow cover this year is still well ahead of the climatological norm.
The relative lack of snow cover in western Canada and Alaska indicates the warm PDO+ that dominated last winter will likely be a major player this winter.
Also, note the very healthy positive snow anomaly in eastern Canada this year! That’s another good sign for us.
The big picture favors a continued rapid spread of snow cover in Eurasia through the end of October into early November with a negative Arctic Oscillation pattern (AO-) suppressing the polar vortices (PV) southward:
Arctic Oscillation:
The Arctic Oscillation has been largely in negative territory for several months. In fact, July and August were near record lows, relative to normal:
The connection between rapid spread of Siberian snow cover and long term AO- is another good sign for a cold winter in the eastern United States.
North Atlantic Oscillation:
The North Atlantic Oscillation had been largely negative this summer, but trending into positive range:
Prolonged NAO- is often a precursor for a cold and stormy winter in the eastern United States. But last winter became brutally cold despite no long stretches of NAO- because the warm PDO+ in the northern Pacific was so dominant. That may be the case again this winter.
El Niño:
No doubt the 2015 El Niño is very strong, but the warmest anomalies are getting pinched away from the South American coast, meaning that El Niño has likely peaked and may start to weaken this winter:
This is no small thing! Western biased El Niño favor colder winters while eastern biased El Niño favor mild winters. If the core of the warm anomalies migrates past 120W toward 150W, the second half of winter could be especially cold and stormy for the eastern United States.
NOAA’s Winter Outlook:
NOAA’s recently released December-January-February temperature outlook seems pretty ominous for snowmobilers and other winter enthusiasts:
To me, this appears to be a boiler plate composite of 1982-83 and 1997-98 El Niño without any regard to the spread of Siberian snow cover or the long term AO-.
NOAA has been slow to embrace Dr. Judah Cohen’s research with Siberian snow cover as a predictor of long term AO- and subsequent cold winters in the eastern United States.
The empirical evidence from last winter suggests that NOAA should place more weight on Cohen’s work because his outlook for December-January-February last winter absolutely crushed it:
If anything, last winter was even colder in the eastern United States than Cohen suggested it would be. But his temperature outlook was light years ahead of the curve compared to NOAA’s weak outlook for last winter:
Believe me, this isn’t to stand on a soap box and smack NOAA. They are the guardian and provider of the information that all meteorologists use to serve the public and private sectors. Without NOAA, I wouldn’t be able to provide accurate weather forecasts for you.
But I am suggesting that visionaries and pioneers like Judah Cohen are sometimes not given proper credit in their time.
You can check out Cohen’s regular updates here.
Bottom line:
If not for the strong El Niño, I would be nearly absolutely certain of another brutally cold winter for ilsnow land, especially for the second half. I’ll gladly take my chances on a cold winter rather than a mild one to get consistent, widespread snow. But I have to respect the fact that El Niño is a significant player and that no two winters are identical.
Notwithstanding the above, I believe that NOAA’s official outlook for a mild winter for the eastern United States could end up being horrifically incorrect, which would be great for us snowmobilers.
For the ilsnow nation,
Darrin
