While large parts of the country were blanketed in snow, frequent invasions of Arctic air increased Great Lakes ice, which had been hovering at record low levels in early January.
Another cold snap, coupled with a storm sweeping across the northern tier, will tighten winter's grip over the weekend. But significant melting is expected next week.
Record snow cover of history
Snow currently covers more than 56 percent of the contiguous United States, after a pair of storms. The first wave swept from the Plains to the Great Lakes last week. It was followed by a second system that produced a band of snow from the mid-south to the northeast between Sunday and Tuesday. The extent of Thursday's snow cover exceeds the previous record of 53.7 percent on this date in 2018. The snow cover data goes back to 2004.
After the record warmth of December, January has seen a sudden shift toward cold and snowy weather. The average temperature across the country for January is 1.2 degrees below average during the middle of the month, amid what is historically the coldest part of the winter. And it's not just snow that expands because of it.
After historic lows, ice cover in the Great Lakes region quickly reappeared over the past week as Arctic air stabilized in the region.
Ice coverage has increased to 10 percent As of Wednesday. Just Since a weekThe average coverage on the lakes was only 1 percent.
While the ice has seen a dramatic turnaround, given the initially small amount, coverage is still well below the average of 22 percent. The ice cover could grow over the weekend but may pause or even recede with expected snowmelt next week.
Annual snow cover typically peaks between mid-February and early March at just over 40 percent. The maximum ice cover varies greatly from year to year but tends to decline as winter temperatures rise due to human-caused climate change.
Fully functional lake effect snow machine
The lack of ice over the Great Lakes has been a boon for lake ice, which requires open water. Often, this snow begins to fall by this point in the season as ice covers the lakes. But with so little ice this year, the open water was a great source of moisture as cold winds swept across the lakes, and snowfall on downwind beaches was plentiful.
Lake snow warnings remain in effect through Thursday evening for locations downwind of Lakes Ontario and Lake Erie, with another 12 to 22 inches of snow expected at hourly rates of up to 3 or 4 inches per hour.
This weekend, another round of significant lake effect snow is expected as a boost to Arctic air diving toward the eastern United States.
Winter storm warnings go into effect Thursday night and continue through Saturday with the wind heading down Lake Michigan. A foot or more of snow is expected in parts of southeastern Michigan and northern Indiana.
Significant snowfall is also expected in the Lake Superior snow belts, and additional heavy lake effect bands will likely target the eastern lakes this weekend, in addition to the heavy snow that fell last week.
In Buffalo, 27.2 inches officially fell through Wednesday, with a foot or two rising in most areas of the snowbelt downwind of the lakes during the same period. A few areas south of Buffalo recorded totals of more than 60 inches between Sunday and Wednesday.
As milder weather returns next week, many of the recent trends toward more cold, snow and ice will be reversed across much of the central and eastern United States.
