Polar vortex 'evaporating' as death toll from US cold snap hits 21
Chicago endured its second coldest day ever recorded on Thursday, but it has been even colder in parts of the upper Midwest.
Friday 1 February 2019 15:27, UK
The brutally cold weather that has caused the deaths of at least 21 people in the US is forecast to end at the weekend as the polar vortex moves away.
The record-breaking cold snap, which has seen temperatures in some parts of the country sink as low as -49C (-56F), will give way to milder, snow-melting temperatures of around 7-11C (45-52F) from Saturday, the US National Weather Service (NWS) said.
"The cold air isn't pushing off anywhere, it's just sort of evaporating," Brian Hurley, a NWS meteorologist, said.
"So we're going from 21 below zero (Fahrenheit) (-29C) in Chicago on Thursday morning to near 50 above (10C) on Monday. It'll feel like a heatwave."
America's third largest city, where about 3.8cm (1.5in) of snow fell overnight into Friday, endured its second coldest day ever recorded on Thursday, but it has been even colder in parts of the upper Midwest.
The coldest recorded temperature was -49C (-56F) in Cotton, Minnesota, on Thursday, when more than 40 cold temperature records were broken, on what was the coldest morning since the polar vortex arrived on Tuesday.
It is all expected to change by Saturday, however, when the region will be basking in highs of between 2C (36F) and 6C (43F), forecasters say.
That may not be enough to change the state of Niagara Falls, however, which has frozen over on the American side.
At least 21 deaths across the US have been linked to the extreme cold, nine of them in Chicago.
Fifty people were treated for frostbite at Chicago's John H Stroger Jr Hospital, including some people who may lose an arm or a leg.
"It's a horrific situation," burn specialist Dr Stathis Poulakidas said.
Frostbite in these extreme conditions can set in as quickly as three to 10 minutes, depending on age or exposure or other factors such as wet gloves and socks and even alcohol consumption, he said.
On Friday, Chicago's Amtrak train services resumed after being stopped on Wednesday, along with US Postal service deliveries in six Midwest states.
Thousands of flights were cancelled and delayed, mostly out of Chicago, according to flight-tracking site FlightAware.com.