Winter 2017: Warmer Along The East Coast, Southern U.S.; Cooler In The Northwest

A mild winter is on its way for the third straight year with much of the United States expected to see warmer than normal conditions though forecasters stopped short of saying temperatures would match the record warmth seen over the last two winters, according to NOAA's winter weather outlook released this week.

Forecasters at NOAA also predict that La Niña, the weather phenomenon that is characterized by unusually cold ocean temperatures in the Equatorial Pacific, has a 55 to 65 percent chance of developing before winter sets in. According to NOAA, if La Niña develops, it will be weak and potentially short lived but could still shape the character of the upcoming winter.

"During La Nina winters, we often see greater than average snowfall around the Great Lakes and in the northern Rockies with less than average snowfall throughout the mid-Atlantic region,” Mike Halpert, deputy director of the Weather Service's Climate Prediction Center, explained in a video. "Regardless of the outlook where you live, be prepared for typical winter hazards such as extreme cold and snowstorms."

The weather phenomenon also means below normal precipitation and drier conditions across the South.

La Niña is not the only factor that determines what the winter may look like, though forecasters say it is the biggest wildcard in how the year's winter will shape up.

Forecasters say warmer-than-normal conditions are most likely along the East Coast, across Hawaii, in western and northern Alaska and across the souther two-thirds of the U.S. Along the northern tier of the country, from Minnesota to the Pacific Northwest and in southeastern Alaska, below-average temperatures are favored, according to NOAA.

For the rest of the country, NOAA says there is an equal chance for above, near, or below-normal temperatures. The winter forecast, Halpert said, is probabilistic in nature, meaning other outcomes are possible, just less likely.

The northern United States, extending from the northern Rockies, to the eastern Great Lakes, the Ohio Valley, in Hawaii and in western and northern Alaska, NOAA predicts wetter-than-average conditions. The southern U.S. is expected to see drier-than-normal conditions while the rest of the country falls into the equal chances category.

In a call with reporters, Halpert was quoted by The Washington Post as saying that climate warming from rising concentrations of CO2 does factor in to NOAA's model forecast. He also said the kind of record warmth seen over the last two winters was not anticipated.

"It would be quite surprising to see a third very warm winter in a row," Halpert said.

NOAA's outlook does not predict snowfall accumulations, which are generally not predictable more than a week in advance. And NOAA cautioned that while the last two winters featured above-average temperatures over much of the nation, significant snowstorms still impacted parts of the country.

Graphic courtesy NOAA