Schools, businesses and roads closed this week in Erie, Pennsylvania, and other cities south and east of the Great Lakes, as a storm dumped three to six feet of snow between last Thursday and Tuesday this week, with more expected.
It might seem counterintuitive, but there has been so much lake-effect snow partly because it was warm this fall. Temperatures in the northeastern U.S., including Pennsylvania, were above normal in October and November.
“What you really have is a signal that the planet, the earth, the region is accumulating heat,” said Richard Rood, professor emeritus in Climate and Space Sciences and Engineering at the University of Michigan.
Because the air is abnormally warm, the Great Lakes are hot, according to Rood. Some spots this time of year are still more than 50 degrees Fahrenheit.
“The water holds the heat far more effectively than the air and even the land,” he said.
So when cold arctic air dipped into the Great Lakes region, “It encountered this incredibly warm water, and hence there’s this enhanced evaporation from the warm water,” Rood said.
That additional water evaporation, mixed with freezing air temperatures, has led to the unusually heavy lake-effect snow, he explained. Climatologists have been predicting this kind of storm because of climate change.
“You are experiencing something that is extreme of our past climate,” Rood said. “But is likely representative of our future climate.”
Pennsylvania Governor Josh Shapiro has already called in the National Guard. Additional lake-effect snow is predicted on Thursday and Friday.
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