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A dramatic weather shift in the Arctic is sending extremely cold air across the Southeast, including southern Florida.
The pattern, caused by unusually high pressure over the North Pole, creates a vast region of dry, sinking air over Greenland that blocks the Arctic westerly winds and shuttles them south.
"These blocking patterns often can persist for weeks on end, and that's what we expect to happen," said Jon Gottschalck, head of forecast operations for the National Oceanic and Atmospheric Administration's Climate Prediction Center. "This is one of the strongest we've ever seen."
Meteorologists call it the cold phase of the Arctic Oscillation and it is responsible for the plummeting temperatures here. In Sarasota, the temperature dropped to a low of 36 degrees early Monday morning, compared with the average 51 degrees. The high was only 52 degrees, 21 degrees below normal. Except for Thursday, high temperatures were forecast to remain below 60 degrees and the lows in the 30s.
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http://www.heraldtribune.com/article/20100105/ARTICLE/1051063/2416/NEWS?Title=Weather-trend-means-chill-may-linger