Here’s the December 31, 2009 snow depth image from NOAA’s National Snow Analysis website:
http://www.nohrsc.noaa.gov/...
It is sobering – regardless of your plans for New Year’s Eve.
What emerges at first glance is the extent of snow coverage – 60% of the continental U.S. has snow cover. But what is more important are the location and depth of this snow cover. Two areas have extensive snow cover and significant snow depth – the Upper Midwest and the Great Basin. The Upper Midwest has snow depths of one to two feet or more. The Great Basin has a foot or more of snow – including the Great Salt Lake Desert.
The Upper Midwest is highlighted in the red triangle – the Great Basin in the Red circle. The yellow lines indicate areas with annual snow cover – the mountains in the West, the Upper Great Lakes, and northern New England - even though snow depth in places like the Sierras fluctuates between wet and drought years. But the extent and depth of snow cover in the Upper Midwest and the Great Basin varies considerably, as well. This year’s snow is the most significant in a decade.
Compare to December 31st in previous years –
2003-2005 were mild. 2006-2008 were moderate.
December 31, 2003 had almost no snow in the East and moderate snow in the Great Basin.
December 31, 2004 had extreme minimal snow cover in the East and in the West.
December 31, 2005 had moderate snow cover in the East and very little in the West.
December 31, 2006 had little snow in the East and West, but moderate snow in the Rockies and Plains.
December 31, 2007 had moderate snow in the East and West, except for the Sierras.
December 31, 2008 had moderate snow in the East and the West.
So it’s been a long time since we entered a new year with this much snow.
http://www.nohrsc.noaa.gov/...
And the snow in the Upper Midwest is not going away any time soon. Average high temperatures in most places in the Upper Midwest in January are below freezing. And that’s an average including years with no snow cover. The albedo effect of snow cover reflects up to 80% of the incoming sunlight. As people who live in the Frost Belt know, once you have a thick snow cover, temperatures plummet – especially at night.
http://www.hprcc.unl.edu/...
Same goes for the Great Basin -
Average Maximum January Temperature
Ely, Nevada
2000 - 41.74
2001 - 33.16
2002 - 33.06
2003 - 48.06
2004 - 27.35
2005 - 29.10
2006 - 40.87
2007 - 30.65
2008 - 30.03
2009 - 39.55
http://www.wrcc.dri.edu/...
January average highs are either 40 degrees or 30 degrees.
If you took a mean high temperature for the decade you would get 35.36.
But that is a false mean since the distribution is binormal – i.e. two humps.
Given extensive snow cover, the odds are that Ely will have a cold January.
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So I’ll venture forth with New Year’s predictions - - since it is December 31st.
Given the extent and depth of the snow cover, it seems highly likely that this winter will be one of the snowiest east of the Rockies. The two major tracks of winter weather – from the Gulf of Alaska and from the Pacific will pass over these pre-refrigerated areas.
In the case of the Upper Midwest, storms coming down from Canada will have a cold reinforcement as counter-clockwise circulation brings additional snow to Kansas and Missouri – possibly Illinois, Indiana, and Ohio as well.
In the case of the Great Basin, unless there is significant melting, cold will tend to pool and chill any moderate Pacific systems as they track into the Four Corners region. These storms are, potentially, far more severe than the Alberta Clippers because they pick up Gulf moisture as they emerge into the Great Plains.
Do not be surprised if on Groundhog Day there is snow
from Dallas to Nashville to Richmond – or more.
Git yer snow shovels out.