This past month of December started much as last December did in Rochester, warm and snow-free. But that changed midway through the month as a new hemispheric jet stream pattern emerged. (The potential of this happening was something we addressed in detail during our winter weather special back in November.)
The new pattern resulted in the greatest national Christmas morning snow cover in a decade, with three times as much of the country covered in Christmas snow than was observed last year. And as of January 1, the U.S. snow cover stood at 67 percent. Last year at the same time, only 20 percent of the country had snow cover.