NOAA states that this year's 'warm winter' over most of the nation has only happened 3 other times since weather recording began in 1890.
It seems NOAA attributes it to a strong La Nina year in combination with the Arctic Oscillation staying to the north and not dipping down into the USA as it usually does during the winter months.
-Diane
And others have chimed in:
"It's certainly not hyperbole to call this a historical weather event," AccuWeather Meteorologist Jim Andrews said. But he's not jumping on the global warming bandwagon just yet.
"If the proposition is that earth's climate is changing -- and most people say warming -- this is how it might manifest," he said. But he believes the unusual weather may be caused by a sort of "perfect storm coincidence" related to North Atlantic oscillation, Atlantic oscillation, the Pacific / North American Pattern, El Nina and La Nina.
"What happens in the oceans is undoubtedly very important to what happens on land," Andrews said. "It may well be that the state of the ocean water temperature surrounding North America is just in an ideal arrangement to maximize warmth over North America."
Expert Senior Meteorologist Alex Sosnowski believes it's a culmination of causes.
"What we're seeing is probably an overlap of several parameters occurring simultaneously. Because of what happened over the winter, you have warm lakes, lack of snow cover. You have a carry over effect, too," Sosnowski said.
"I think the biggest thing in my opinion would be arctic oscillation. It trapped most of the arctic air in the far north and allowed milder air to sweep across Canada and much of the U.S."