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Forecasters: Old Man Winter finally shuffling out the door

Brian Snyder / Reuters file

A forecaster said spring should finally arrive this week, after prolonged wintery weather brought scenes like these in mid-March in Boston.

Much of the northern U.S. may be shivering with some areas 20 degrees below normal, but forecasters said Tuesday this could be the last cold blast until next fall.

A long winter of punishing blizzards, frightening wind chills and dangerously slippery roads appears to be finally going away, according to Weather.com meteorologists.

"We had this persistent trough in the East, and winter just wouldn't give up," Dale Eck, director of the Weather Channel's Global Forecast Center, said.

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As the week progresses, a clear trend emerges on National Weather Service forecast maps of daytime highs: Across the nation, the light pink and deep purple associated with below-freezing temperatures all but vanish, replaced by the aquamarine and deep green of the 40s to 60s.

An unusually cold March meant many areas – the Weather Channel's home in Atlanta, for instance – had colder average temperatures in March than in January.

"The psychology here is that … people didn't get that taste of spring," he said. "Once you get out of this cold pattern, it's very quickly going to feel very warm and springlike."

It's not quite over yet. Temperatures will struggle to approach freezing in the Northern Plains on Tuesday, and tapering lake-effect snows are likely to remain for a day or two in areas from the Upper Midwest to Western New York and Pennsylvania.

Arie Kievit / EPA

Warming weather and longer days bring out the first signs of Spring.

The far north remains subject to arctic winds from Canada.

But the jet stream, which pulls that cold air with it as it makes southern incursions in the U.S., appears to be settling into its northerly position, Eck said.

"After this current shot of cold air, it looks like the jet stream is going to relax and park itself close to the Canadian border," he said. "That will allow the southern half of the United States to get above average, so that's going to feel different."

"It's just going to be a major shift."

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