Harsh Winter Outlook Made a Bit More Dire by Siberia Snow
By Brian K. Sullivan
Remember how evidence was mounting last month that early snowfall was accumulating across Siberia? And remember how there’s a theory that says this snowfall signals a cold winter?
So in the two and a half weeks since, the news for the winter-haters has, unfortunately, only gotten worse.
About 14.1 million square kilometers of snow blanketed Siberia at the end of October, the second most in records going back to 1967, according to Rutgers University’s Global Snow Lab. The record was in 1976, which broke a streak of mild winters in the eastern U.S. In addition, the speed at which snow has covered the region is the fastest since at least 1998.
Taken together they signal greater chances for frigid air to spill out of the Arctic into more temperate regions of North America, Europe and Asia, said Judah Cohen, director of seasonal forecasting at Atmospheric and Environmental Research in Lexington, Massachusetts, who developed the theory linking Siberian snow with winter weather.
“A rapid advance of Eurasian snow cover during the month of October favors that the upcoming winter will be cold across the Northern Hemisphere,” Cohen said in an interview yesterday. “This past October the signal was quite robust.”
There are a few steps to get from the snows of Siberia to the chills in New York City.
Cold air builds over the expanse of snow, strengthening the pressure system known as a Siberian high. The high weakens the winds that circle the North Pole, allowing the cold air to leak into the lower latitudes. The term Polar Vortex actually refers to those winds, not the frigid weather...