UK & World News
Polar Vortex To Plunge US Temperatures to -50C
Windchills of nearly -50C (-60F) are threatening to turn states in the north and northwest US into an icy deep freeze.
A phenomenon described as a polar vortex is set to suck super-chilled air from the Arctic into North and South Dakota, the Great Lakes states and New England, sending temperatures plunging.
Washington DC has already seen its coldest temperatures for 20 years and several states in the Midwest have recorded their lowest mercury readings for more than a decade.
Icy weather is feared to have been a factor that led to a Delta Airways flight skidding off the runway at JFK Airport on Sunday.
None of the flight's 35 passengers were injured and the aircraft was safely towed to a gate.
The busy New York airport suspended operations for about two hours due to slick runways.
In Chicago, about 1,200 flights have been cancelled at the city's O'Hare and Midway international airports.
Weather Bell meteorologist Ryan Maue described current weather conditions as a once in a generation event.
"If you're under 40 (years old), you've not seen this stuff before," he said.
With much of the northeast of the country already under thick snow and well below zero, a newly emerging weather system is threatening to cause further misery.
The 'polar vortex' is an anti-clockwise rotating pool of cold, dense air that forms close to the North Pole, but typically hangs over Canada.
Meteorologists say that unusually, this year, it is heading south and moving towards the north and eastern United States.
Fargo in North Dakota is expected to dip to -31C (-25F), International Falls, Minnesota will fall to -35C (-31F) and Indianapolis, Indiana and Chicago, Illinois, will reach -26C (-15F).
Forecasters say that at those temperatures exposed skin can get frostbitten in minutes and hypothermia can quickly set in as wind chills may reach 50, 60 or even 70 below zero F (45.5, 51 or even 56.7 below zero C).
The frigid forecast prompted Minnesota public school officials to announce a statewide closure for Monday, marking the first such mass closing in 17 years.
The Wisconsin cities of Milwaukee and Madison have also announced school closures to start the week.
Also in Wisconsin, Sunday's NFL playoff game at Green Bay's Lambeau Field could be among the coldest ever played, with temperatures at kickoff expect to be at -19C (-2F).
The coldest NFL game on record was the 1967 Championship Game at Lambeau between the Packers and Dallas Cowboys. Temperatures for that game - dubbed The Ice Bowl - fell to -25C (-13F).
Elsewhere, parts of New England have already dropped into the negatives with some places hitting -35C (-30F) in Vermont and -38C (-36F) in Maine.
At least 16 deaths have been blamed on a snow storm that swept across the eastern half of the US at the end of last week.
Only a few thousand people have been left without power in the US despite heavy snowfalls, but in Canada, which has seen unusually heavy snow in a country used to cold winters, nearly 90,000 are without power in Newfoundland.
Temperatures were also expected to plummet to -35C in northwestern Ontario and Environment Canada issued a special weather statement on Saturday night for much of southern Ontario, warning of heavy snowfalls.
Meanwhile, in Brazil, soaring temperatures in Rio de Janeiro set off fire sprinklers in shopping malls as the thermometer topped 40C (102F).
Thousands headed to the beach as temperatures rose to more than 50C in the sunshine.
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