Meteorological winter begins tomorrow (Meteorologists divide the seasons up into quarters; December, January and February is the winter season.)  As a weather enthusiast, I look at fall, using a sports analogy, as the pre-season.  If you are a football fan, every fall you hope your team is going to the Super Bowl, or at least the play-offs.  So, yes, I’m hoping and I hope every year, that the coming winter will be the “Super Bowl” of winters. 

Last was disappointing for us winter lovers.  November was warm; over three degrees above average.  I’ve looked back at winters with warm Novembers and the it is true that “Winter will Remember the Pattern of November”—at least for very warm Novembers.  In the 136 years of record for Marquette and the National Weather Service (NWS) site near Negaunee, there have been 42 Novembers three or more degrees above average.  Out of those 42, 36 of the following winters were warmer than average; that’s 86 percent!  

On the other hand, for Novembers that were somewhat warm (0.1 to 2.9 degrees above average), the result is different.  I counted 36 Novembers of this type in the record.  Out of the 36, only 16 had warmer than average winters, or 44 percent.  In other words, a little warmer than average November actually tilts the odds toward a colder than average winter.  November 2012 will be one of these Novembers.  It will end around 2.5 degrees above average.  The first week was cold, the middle two warm, with the period around Thanksgiving exceptionally warm and then the last week has been cold.  So that, at least mildly, points toward a cold winter.  There is a caveat here; there were a number of warm Novembers in the late 50s through the 1970s.  That was a cold cycle, so winters were cold.  We are now in a warmer cycle. 

Last year, the pattern was quite a bit different than this year over North America and over the Oceans.  A mild westerly flow dominated much of North America during November keeping the really cold air bottled up in the arctic (Image 1 above).  This pattern was established in October and essentially held through the winter.  This November has displayed a different pattern, more conducive to cold weather.  The map for the same day as last year showed a deep, cold upper-air low or vortex covering much of Canada (Image 2).  This allowed some very cold air to spread across the country and dip, at least briefly, into the northern United States.  On the other hand, the cold will not hold here because of a big upper-air trough over the Gulf of Alaska to off the West Coast.  This system sends mild Pacific air eastward across the country.  As long as this system remains in that location or reforms there, cold, wintry weather will not stick around here very long. 

The Ocean temperatures look different this year compared to last year and will likely have an impact on the weather here this winter.  Last year, the Pacific Ocean off North America was very cold, while there was a large warm patch of water that held all winter northwest of Hawaii (Image 3).  This pattern worked to hold the trough over the Gulf of Alaska and kept us mild.  In the North Atlantic, the water was relatively cold and that tended to hold storminess over that region.  That was another plus for mild weather here. 

This year, the waters of the North Atlantic are much warmer compared to average, while there’s a cold patch of water off Spain (Image 4).  Meteorologist Joe D’Aleo (AKA Dr. Dew Point) has shown that this tends to lead to blocking high pressure developing over the North Atlantic.  We had that in late October, which led to Hurricane Sandy making the anomalous turn into New Jersey.  That is a plus for cold winter weather over eastern North America. 

The cold that has developed over Canada has a long-term impact, in that cold begets cold.  Last year at the end of November, snow cover was sparse over western Canada and Hudson Bay had almost no ice (Image 5).  This year, there is a good snow cover over virtually all of Canada and Hudson Bay is icing up fast because of the intense cold of late (Image 6).  That means that arctic cold coming out of the Yukon where temperatures have been near 50 below in a few locations will not get a chance to modify as it filters south..

On the other hand, the first few days of December look like a repeat of the Thanksgiving warm spell, only this one should not last as long.  There are a signs that the pattern will evolve into a colder one in the long term.  The European ensemble forecasts a deep trough over the central U.S. in 10 days (Image 7).  At the same time, a ridge is building in the eastern Pacific.  If this scenario unfolds, it will turn colder and hold for a while during the second week of December. 

Over the winter, my bet is for an average winter.  While there are a number of signs that point toward potential cold, the eastern Pacific trough is still showing up on a consistent basis.  When the trough weakens the cold will charge south.  If it’s accompanied by blocking, there is a chance of some bitter cold—something we have not felt in several years.  On the other hand, with the Pacific rather muddled, troughing is likely to form on occasion from the Gulf of Alaska to the West Coast.  Then the floodgates will be open to thawing weather. 

As for snow, our long-term dry spell continues and will probably not break down this winter.  I see below average snowfall again this winter over the southern U.P. away from the Lake Superior snow belts.  Farther north, the available cold in Canada will likely lead to more average snowfall this year as opposed to the sub-par last couple of winters.