Latest Great Lakes’ Ice Cover

January 25, 2012 0 Comments




As you probably know, the winter so far has been quite a bit warmer than normal.  It stands to reason then that there would be less ice cover on the Great Lakes than usual for this time of the year.  According to the map below from NOAA, it appears that about 90% of the surface of the Great Lakes are still ice free.  Some of the shallower portions and edges of the lakes are froze over.  For example the Bay of Green Bay is pretty much covered along with areas near the coast around Ashland and Bayfield.  A small area northwest of Isle Royale in Lake Superior is ice covered.  So are a few pockets in southwest Lake Michigan and near the Mackinac Bridge.  The portion of Lake Huron that is most covered with ice is the little finger that juts out north of Saginaw.    Lake Erie has some ice cover on its western flank.








There are a few interesting implications from the lack of ice cover on the Great Lakes.  One is that if  some cold arctic air  actually comes across the open waters there should be high amounts of lake effect snow.  The long fetches of relatively warm, moist air over the lake rising up into cold arctic air masses are the perfect set up to produce lake effect clouds and snow.   It’s probable large parts of the lakes may stay open right into spring, so I see no reason why the lake effect snow would shut off in February, like some years.  Secondly, winds off the lakes will tend to keep temperatures a bit milder in the Great Lakes States than they would be if they were completely iced over.  


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About the Author:

StormTrak9 Meteorologist with WAOW-TV in Wausau, WI. Also the owner of Great Lakes Weather Service, LLC.

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