Thousands of flights have been cancelled as a "life-threatening" blizzard hits the US.
Around 50 million people have been told to batten down the hatches and prepare for Storm Stella.
The National Weather Service issued blizzard warnings for parts of Pennsylvania, New Jersey, New York and Connecticut.
Snow has already started to fall in some areas and there are forecasts of up to 2ft expected by early Wednesday.
Temperatures have plummeted 15 to 30 degrees below normal for this time of year.
Several states have already declared a state of emergency, including New York and New Jersey.
The weather service’s office near Philadelphia called the storm “life-threatening” and warned people to “shelter in place.”
At least 5,300 flights have been cancelled, including many from the UK to parts of the US.
A White House visit by German Chancellor Angela Merkel has been delayed until Friday because of the storm.
Will your travel be affected?
British Airways said their flights are "significantly affected" and have cancelled flights to New York JFK, Newark and Philadelphia on Tuesday.
It added there will be no flights from London Heathrow to Boston.
There will still be some flights to/from Washington and Baltimore but schedules may be revised.
Virgin Atlantic has cancelled flights from Heathrow to New York JFK and some flights to Boston and Washington.
Virgin Atlantic say on their website that customers booked to travel to, from and through Boston, Washington, New York JFK and Newark on 15 - 17 March 2017, who prefer to rebook may do so without penalty.
It added that rebooking is subject to availability in the same cabin for flights and travel must be completed on or before 24 March 2017.
American Airlines is advising passengers they may be able to change their trip with no change fee due to severe weather.
Many flights have been cancelled - including some flights from Heathrow Airport - and it has listed all the affected airports on its website.
Many flights are cancelled and United will allow you to change your flight due to severe weather if you are travelling from an affected airport.
Some Lufthansa flights from Heathrow Airport to the US are also operated by United Airlines and have been cancelled.