Early Winter Weather Brings Snow Cover to 50% of U.S.

The winter of 2014 - 2015 is off to an early start over the continental U.S., where snow covered 50% of the nation as of November 17, 2014. This is an unusually high percentage for mid-November; over the past ten years, the percentage of the continental U.S covered by snow on November 17 has ranged from 4% - 20%. Most of this year’s November snow cover is going to stick around this week, as a renewed Arctic blast will keep temperatures 10 - 30°F below average through Friday for most of the nation. Temperatures will not moderate to near average levels until next Sunday. Extremely cold air flowing over the waters of the Great Lakes will create an epic lake effect snow storm today through Wednesday, particularly in the lees of Lake Erie and Lake Ontario, where the west-southwesterly winds of the storm will align with the long axis of these lakes, allowing the air to pick up large amounts of moisture from the unfrozen water. A Lake Effect Snow Warning is in effect for Buffalo, New York, where almost two feet of snow is expected to pile up by Wednesday afternoon. Southwest winds of 20 to 30 mph with gusts to 45 mph blowing off of Lake Erie are expected late Monday night through Tuesday night, and may create blizzard conditions with visibilities near zero. Blizzard conditions are uncommon in lake effect snow storms, and this week’s storm will likely be one of the worst lake effect snow storms for Buffalo in the past five years. Up to three feet of snow is expected in the lee of Lake Ontario near Watertown, New York. Lesser snow amounts are expected in the lees of the other Great Lakes, where the wind will not be blowing over such long stretches of open water. Up to 18” of snow is expected in the lee of Lake Michigan in northern Lower Michigan near Bellaire, and in the lee of Lake Superior near Pictured Rocks National Lakeshore.


Figure 1. U.S. snow cover as of 1 am EST November 17, 2014 showed 50% of the lower 48 states were covered by snow. Image credit: NWS NOHRSC (thanks to TWC’s Tom Moore for providing the graphic.)


Figure 2. Snowfall forecast for this week's lake effect snow storm. Over 2' of snow is expected in the lee of Lake Erie just south Buffalo, and in the lee of Lake Ontario near Watertown. Image credit: NWS Buffalo.

Jeff Masters