"It could be one of the coldest (U.S. winters) in this decade, depending on what happens in the West," says Matt Rogers, a forecaster with the Commodity Weather Group, a consultancy with clients in the energy and agriculture industries. "We feel like we need to watch this particular winter closely."

Temperatures could be 5% to 10% below normal, Rogers says. However, he and others also predicted a milder-than-usual winter across other northern states.

The possibility of an extraordinarily cold winter is troubling to safety officials in the Northeast.

"The more snowfall we get, it does correlate to more accidents and cars off the road and people we assist off the highway," says Sgt. Ian Berkeley of the New Hampshire State Police. But "being a New Englander, we always expect the worse in the winter."

Forecasters are basing their predictions on El Niño, a periodic warming of the tropical Pacific Ocean that can bring warm air to the north. Forecasters say El Niño will be weaker than normal this year.

"Historically when you have that El Niño on the weak side, it tends to correlate to colder weather in eastern North America," Rogers says.

Cooler-than-normal weather is also likely in the South from Texas to Florida, says Jeff Masters of the private forecasting group Weather Underground.

A weak El Niño also correlates with milder-than-normal temperatures elsewhere across the northern tier, says Jon Gottschalck, head forecaster at the federal Climate Prediction Center in Maryland.

He predicts warmer-than-average temperatures for the upper Midwest, the central and northern Plains, the Rockies, and the Northwest.

Contributing: Doyle Rice

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