Winter storm Jonas is set to affect almost 76 million people as several feet of snow hit the north-east US, causing travel chaos for millions as internal flights are grounded and international flights under threat of cancellation.
The storm is expected to bring heavy snowfall to 15 states, with blizzard warnings, plunging temperatures and coastal flood warnings in place from 22 to 24 January.
The blizzard warning, which is set to remain in place across the weekend and has already grounded almost 2,000 flights, means conditions are likely to include heavy snow, strong and "potentially damaging winds", with travel cited as dangerous, according to the US National Weather Service.
The service also rolled out advice for those travelling, with potential whiteouts leading NWS to suggest drivers stay with their vehicle if they get stranded while travelling, and to pack a winter survival kit including food, water and a torch in case of emergencies, if travel is absolutely necessary.
While the majority of grounded flights currently are US domestic carriers, Heathrow Airport warned that transatlantic flights could face cancellation.
A spokesperson for Heathrow Airport told IBTimes UK that some cancellations at the moment may be expected, more so over the weekend, also advising passengers to check with individual airlines before they begin their journey to the airport.
More than 35 US cities are facing the impact of Storm Jonas over the weekend, meaning flights to a variety of US airports could be cancelled.
Temperatures across the north-east US are also set to plunge to below freezing on 23 January, with conditions including snow, ice and potential coastal flooding set to worsen across the weekend before improving on 24 January.