The snow in Siberia is piling up, and if it keeps coming, people in New York may have to bundle up this winter.
There's a theory that the amount of snow covering Eurasia in October is an indication of how much icy air will sweep down from the Arctic in December and January, pouring over parts of North America, Europe and East Asia.
Last year, the snow level across Eurasia was the fourth highest for the month in records going back to 1967. In January, frigid temperatures dubbed "the polar vortex" slid out of the Arctic to freeze large portions of the U.S.
It was a pattern that repeated itself during the Northern Hemisphere winter and helped make the first three months of this year the coldest in the 48 contiguous states since 1985.
With the snow now piling up across Eurasia, will this winter be a grim reminder of last year's?
"It's still early in the game," said Judah Cohen, director of seasonal forecasting at Atmospheric and Environmental Research in Lexington, Mass.
While "the snow has gotten off to an incredible start," Cohen said, he needs to see how much covers the area through the entire month before he can make an accurate forecast. The National Science Foundation has sponsored his research.
As of Oct. 13, Cohen calculated, snow covered 4.7 million square miles of Eurasia, compared with 4.1 million square miles on the same day last year.
It's important to note that snowcover ebbs and flows. Last year, some of it melted away before Oct. 31 arrived. Cohen said the same may happen this year.
According to Cohen's research, there's a link between snowcover, how much cold spills out of the Arctic and where it ends up once it escapes.
A big piece of this depends on the North Atlantic Oscillation, or NAO, which is a pressure differential across the basin. When it's in its negative phase, cold air can be bottled up across the eastern U.S.
Cohen said we need to wait a few weeks before he'll predict what will happen. "Our research has shown that you need all 31 days" of October, he said. "A lot can go wrong."
