In October, StormTeam 16 Chief Meteorologist Mike Hoffman outlined his preliminary winter outlook for this year.
Mike still predicts for much more of a winter this year than last year. But, as we head towards December and the temperatures start to drop, here’s Mike’s final verdict.
The last two winters have been polar opposites of each other. Last winter was almost nothing. Five degrees warmer than normal overall, and 15" less snow than normal. The year before was a doozie, though. Two and a half degrees colder than normal with a whopping 105.6 inches of snow--almost 40 inches more than normal. Both were La Nina winters in the Pacific, which proves you can't just go with La Nina or El Nino when forecasting the winter.
Going to the Pacific will give us lots of information. An El Nino, or warm water near the equator was supposed to develop, but as of now, we are not officially in an El Nino at all. There is some warm water in the central Pacific, but it's not quite considered an El Nino. When we go to the north Pacific, we continue to be in a "cold" phase of the P.D.O., or Pacific Decadal Oscillation. This is the main reason, I believe, that worldwide temperatures have leveled off in the last 12 years. It's a 30 year cycle, and this set-up would lead to a flow like this. Across the continent to the Atlantic, I'm still watching the A.M.O., or Atlantic Multi-decadal Oscillation. It's still in the "warm" phase, but this warm water where it is would typically give a flow northward in the Atlantic. Overall, then, the flow, or Jet Stream, should end up looking like this a lot, which would bring many shots of cold air southward.
There are 7 past winters that were similar situations to this one--when you take into account the overall ocean temperature set-up--all of them also weak, or not quite, El Ninos. The average amount of snow in those winters was almost 5" more than normal, but the average temperature was about ½ degree milder than normal.
You might notice that 4 of these winters are from the 1950's; a decade known for huge east coast hurricanes. Eight of those hurricanes were stronger than Sandy of this year, but they didn't quite hit the populated area like she did. So we are in a similar pattern. We also have to remember that Lake Michigan has been warmer than normal since the hot summer, which could lead to more lake-effect snow early in the season.
From there, I looked at several other recent items. First, the last 3 ½ months have been colder than normal, which has been a trend. Another factor is snow-cover. There is more of it than usual over western North America, where our air will be coming from. Also, the long-range computer models have flipped from warm a month or two ago, to near normal or colder than normal for us now. And finally, starting next week, we are heading into a short-term Atlantic pattern that suggests cold temperatures for the Great Lakes and east, and a quick shift to winter.
So, taking all of that into account, here is my final Winter Forecast for the winter of 2012/2013:
I expect temperatures to be only slightly colder than normal, by about ½ degree, at 26.5 degrees for December, January and February. That would be almost 6 degrees colder than last year--a lot. As for snow, I will stick with what I had earlier, at 76" of snow for the entire season. That's almost 10" more than normal, but more than 2 feet more snow than last winter.