Millions of people across the US scrambled yesterday to make last minute preparations for an unusually chilly Arctic blast that sent temperatures plummeting to the coldest in 20 years.
The northeastern US and parts of Canada have experienced heavy snow and deadly sub-zero conditions since the start of the year, the frigid conditions were now moving through the midwestern US and threatening usually warm areas further south like Tennessee and Alabama.
The wind chill from the rare " polar vortex" could make the cold seem like -60 Fahrenheit (-51 Celsius) in places, according to weather forecasters, a prospect which saw authorities in several towns and cities issue warnings that people keep indoors and stock up on food.
According to experts, exposed skin could suffer frostbite in as little as five minutes under such conditions.
Describing the weather as ''life-threatening,'' the National Weather Service said, the coldest temperatures in decades would spread into the northern and central US today behind an Arctic cold front.
"Combined with gusty winds, these temperatures will result in life-threatening wind-chill values as low as 60 degrees (Fahrenheit) below zero. Also, heavy snow will develop from the eastern Plains to the Great Lakes today, with up to a foot of accumulation possible."
Meanwhile, the ''polar vortex'', frigid, dense air that is threatening to shatter temperature records and send wind chills to dangerous levels would hit the Midwest and south US.
Temperatures are expected to plunge 15 degrees below zero in Chicago, Indianapolis and Minneapolis, 21-below in Madison, Wisconsin and over 30-below in Fargo, North Dakota.
According to CNN, temperatures in about half the country could be below-zero by Wednesday.
Officials in Chicago, St Louis and Milwaukee have closed schools and flight delays have been reported to be persisting across the country after cancellation of thousands of flights and delays due to the earlier blizzard, creating a travel backlog at airports.
Overnight temperatures in Atlanta and Birmingham are expected to be in single digits, and Jacksonville, Florida, would see temperatures dip to about 20 degrees, the Wealdther Channel reports.
Officials, meanwhile have been cautioning against extended stay outside and were reminding all to dress adequately and in several layers, as frostbite and hypothermia would be a real danger at such low temperatures.