Temperature records could fall as U.S. braces for 'polar vortex' conditions (2 video)

The deep freeze expected to arrive Sunday in parts of the United States will be one to remember, with potential record-low temperatures heightening fears of frostbite and hypothermia.

It hasn't been this cold for decades -- 20 years in Washington, D.C., 18 years in Milwaukee, 15 in Missouri -- even in the Midwest, where bundling up is second nature. Weather Bell meteorologist Ryan Maue said, "If you're under 40 (years old), you've not seen this stuff before."

Blame it on a "polar vortex," as one meteorologist calls it, a counterclockwise-rotating pool of cold, dense air.


"It's just a large area of very cold air that comes down, forms over the North Pole or polar regions ... usually stays in Canada, but this time it's going to come all the way into the eastern United States," said National Weather Service meteorologist Phillip Schumacher in Sioux Falls, South Dakota.

The frigid air -- a perfect combination of the jet stream, cold surface temperatures and the polar vortex -- will begin Sunday and extend into early next week, funneled as far south as the Gulf Coast.

The forecasts are startling: 25 below zero Fahrenheit (31 below zero Celsius) in Fargo, North Dakota, minus 31 F (minus 35 C) in International Falls, Minnesota, and 15 below F (26 below C) in Indianapolis and Chicago. 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).

Even wind chills of 25 below zero F (31.5 below zero C) can do serious damage, according to National Weather Service meteorologist Scott Truett in St. Louis.

"Those are dangerous levels of wind chill," he said of the expected wind chill in Missouri at daybreak Monday. "A person not properly dressed could die easily in those conditions."

Already, parts of the northeastern New England states dropped into the negatives early Saturday, with East Brighton, Vermont, seeing 30 below zero F (34.4 below zero C) just after midnight and Allagash, Maine, hitting minus 36 F (minus 37.8 C). The cold will sweep through other parts of New England where residents are digging out from a snowstorm.

Snow will reduce the sun's heating effect, so nighttime lows will plummet because of the strong northwest winds, Maue said. Fresh powder is expected in parts of the central Midwest and South starting Saturday night -- up to a foot (30 centimetres) in eastern Missouri and southern Michigan, 6 to 8 inches (15 to 20 centimetres) in central Illinois, 8 or more inches (20 or more centimetres) in western Kentucky and up to 6 inches (15 centimetres) in parts of middle Tennessee.

The South also will dip into temperatures rarely seen. By Monday morning, western and central Kentucky could be below zero F (minus 18 C ) -- "definitely record-breaking," said weather service meteorologist Christine Wielgos in Paducah, Kentucky. And in Atlanta, Tuesday's high is expected to hover in the mid-20s F (around minus 4 Celsisus).

Sunday's National Football League playoff game in Green Bay could be among one of the coldest ever played -- a frigid minus 2 degrees F (minus 19 degrees Celsius) when the Packers and San Francisco 49ers kickoff at Lambeau Field. Medical experts suggest fans wear at least three layers and drink warm fluids -- not alcohol.

Minnesota has called off school Monday for the entire state -- the first such closing in 17 years.

Before the polar plunge, Earth was as close as it gets to the sun each year on Saturday. The planet orbits the sun in an oval and on average is about 93 million miles (149.7 million kilometres) away. But every January, Earth is at perihelion, and on Saturday, it was only 91.4 million miles from the sun. But that proximity doesn't affect the planet's temperatures.

Maue noted that it's relatively uncommon to have such frigid air blanket so much of the U.S., maybe once a decade or every couple of decades.

At least 16 deaths were blamed on a snow storm that swept across the eastern half of the U.S., including three people who officials said died at least partly because of the extreme cold.

The snowfall had all but stopped by Friday morning in the hard-hit Philadelphia-to-Boston corridor and though the temperatures reached only the teens or single digits F (up to about minus 7 C) , the cold kept the snow powdery and light.

The heaviest snow fell north of Boston in Boxford, Massachusetts, which received nearly 2 feet (60 centimetres). Nearly 18 inches (45 centimetres) fell in Boston and in western New York near Rochester. New York's Central Park got 6 inches (15 centimetres), and Philadelphia got more than 6 inches (15 centimetres).

Warming centres opened around the region, homeless shelters received more people, and cities took special measures to look after those most vulnerable to the cold. Teams in New York City searched the streets for homeless people.

The light, powdery snow fortunately did not weigh down electrical lines or tree limbs, and as a result there were only a few thousand power outages across the U.S. Northeast.

However, in Canada, a transformer malfunctioned at the terminal station in Sunnyside, Newfoundland, after an overnight blizzard, knocking out power to 190,000 customers. About 125,000 people remained without power Saturday afternoon, mostly in eastern parts of Newfoundland.

Associated Press Writer Seth Borenstein in Washington and Bill Draper in Kansas City, Missouri, contributed to this report.

ctvnews.ca
 ajc.com
4/1/13 
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Neige et vague de froid dans le nord-est des Etats-Unis et l'est du Canada