A lack of Pacific Ocean warming and of blocking patterns in the Atlantic will probably mean warmer- than-normal weather in the eastern U.S. for the next three months, said Todd Crawford, chief meteorologist at Weather Services International.
Temperatures in the East may be about 2 degrees Fahrenheit (1 Celsius) above normal from November through January, while the Northwest cools, according to a seasonal forecast today from the Andover, Massachusetts-based company.
“It is now clear that the previously expected El Nino event is dead on arrival heading into the winter season,” Crawford said in a statement, referring to the Pacific warming phenomenon. “We expect the strongest signal this winter will be for cold Alaskan high pressure to direct cold Arctic air southward into western Canada and the northwestern U.S.”
Above-normal temperatures in the Midwest and Northeast can crimp demand for natural gas and heating oil to warm homes and businesses. In the winter of 2011-2012, mild weather sent natural gas futures to a 10-year low by April.
Last winter was the fourth-warmest on record in the contiguous 48 states, with an average temperature of 36.8 degrees Fahrenheit (2.7 Celsius), according to the National Climatic Data Center in Asheville, North Carolina.
“The biggest wild card heading toward this winter is the degree of atmospheric blocking in the North Atlantic, typically referred to as the North Atlantic Oscillation,” Crawford said.
The oscillation, a pressure differential over the ocean and Greenland, can bottle up cold air in North America if conditions are right. In the winters of 2009-10 and 2010-11, the blocking sent temperatures plummeting.
In 2012, the North Atlantic Oscillation didn’t have much of an impact and temperatures were warmer. Crawford said he doesn’t expect it will play a large role this winter, either.
“Recent climate model forecasts and statistical predictors generally suggest that Atlantic blocking will be the exception rather than the rule this upcoming winter,” Crawford said. “And we feel that the odds are tilted toward another mild winter across much of the eastern U.S.”
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