Freezing Arctic air and high winds have blasted the United States and driven air temperatures in parts of the American midwest and northern plains to their lowest levels in almost two decades.
Temperatures falling to near-record lows led to warnings about “life-threatening” wind chills – what the outside air feels like when high wind is factored in – and the threat of frostbite and hypothermia.
The midwest bore the brunt of the freezing polar air as Duluth in Minnesota, near the border with Canada, recorded a wind chill temperature of -49°, the lowest in the country.
Cold air mass
Freezing weather has brought the coldest temperatures in years as far south as Atlanta and Nashville as the cold air mass has moved east towards Boston, New York and Washington DC.
It is estimated that as many as 140 million Americans, almost half the country's population, have been affected by the cold spell, leaving parts of the Deep South colder than Alaska.
Temperatures were expected to fall to freezing or close to it in parts of Florida today.
The National Weather Service (NWS) warned that wind chills continued to remain as low as -29° to -46° across the central and eastern US.
The cold spell has followed soon after a front that brought a foot of snow and high winds to the midwest and northeast, making driving treacherous in many parts and shutting down cities.
Meteorologists said a “polar vortex” had affected the traditional west to east airflows across the country blowing cold, dense winds counterclockwise south from the Arctic.
Arctic high pressure
"Arctic high pressure that originated in polar regions has worked its way down. What makes it unique is the combination of strong winds with frigid temperatures," Brad Temeyer, a meteorologist at the NWS in Sioux Falls, South Dakota, told The Irish Times.
Mr Temeyer said the cold front blowing can make a temperature of -29° feel like -45° in a wind of 15 to 20mph.
Indianapolis banned drivers from the city’s roads except for emergencies or where motorists were seeking shelter, in the first “red” travel warning issued by the city since a blizzard in 1978.
Air travellers were left stranded at airports as more than 3,000 flights were cancelled yesterday and another 3,000 were delayed, according to the flight-tracking website FlightAware.
Temperatures at Chicago’s O’Hare International Airport, the worst affected by the freezing weather, fell to a degree below a record of -26° set in 1988, according to the NWS.
'Chi-beria'
Chicago, dubbed "Chi-beria" on social networking website Twitter, ordered the closure of public schools, while the governor of Minnesota, the midwest state accustomed to freezing temperatures and heavy snowfalls every year, took the unusual step of closing all schools for the first time in 17 years.
Drivers in North Dakota and South Dakota were warned to carry winter survival kits and charged mobile phones in case they became stranded in temperatures where frostbite can set in within minutes.
The NWS Twin Cities office in Minnesota warned that exposed flesh could freeze in as little as five minutes in wind chills of colder than -45°.
At least 13 people are reported to have died from weather- related conditions over the past week, including 11 in road accidents.
Britain
Britain remains at risk of more flooding as rain continues to plague the south of the country and tidal surges batter the coast.
The huge waves prompted the Environment Agency to sound its flood siren in Dorset last night – warning of extreme danger to people and property
The alarm was raised after the sea breached Chiswell Beach in Portland around 10pm and spray crashed over flood defences, the Weymouth and Portland Coastguard said.
Residents, who had been on high alert for hours, were told by Dorset Police to move to an upstairs room facing away from the sea and it is believed some homes were evacuated.
The coastguard reported “horrendous” sea conditions and road closures.
Three severe flood warnings — the highest level of warning — have been issued by the Environment Agency covering Chiswell, nearby Preston Beach and the Lower Stour in Dorset.
More than 120 flood warnings urging people to be prepared for flooding remain in place across the country, including in Dorset, Oxfordshire, south Wiltshire, Hampshire and along the river Thames, while more than 200 low-level alerts have been issued.
The Met Office said that heavy showers, some of them combined with hail and thunder, will continue to affect parts of southern and south-eastern England today and tomorrow.
The rain is falling on already saturated ground after a succession of storms putting added pressure on already swollen rivers, while coastal areas also battle high tides and strong winds.
Many areas have faced disruption from road closures and cancelled or delayed train services as people returned to work after the Christmas holidays.
Seven people have died and more than 1,700 homes and businesses have been flooded in England since the beginning of the Christmas period, with 300 properties flooded since the New Year. Some 140 properties have been flooded in Wales.
High winds over Christmas also left 250,000 homes without power, with some families waiting days for the electricity to be restored.