A snowstorm is barrelling down on parts of the US east coast with more than 60 million people under a winter storm watch.

The storm is expected to stretch from Colorado to Maine and warnings are in place in 14 states.

Some places are predicted to see as much as two feet (60cm) of snow.

The National Weather Service (NWS) has warned of "dangerous, if not impossible travel conditions and isolated power surges" in the worst affected areas.

The heaviest snow is predicted to fall on Wednesday evening. The NWS said some areas will see more snow "in one event than they have seen all of last winter".

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image captionCoronavirus testing in a number of states has been suspended

In New York, Mayor Bill de Blasio has warned that the storm could be the biggest the city has seen in several years.

He warned residents to "take this seriously".

Schools across the city have moved to online learning, outdoor dining has been suspended and ferry routes in the city have stopped.

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Hundreds of flights have been cancelled and rail services suspended across the northeast.

US Secretary for Transportation Elaine Chao warned those in the path of the storm "to know that's expected for your area and don't drive in dangerous conditions".

IMAGE COPYRIGHTREUTERS

image captionThe storm has forced airlines to cancel hundreds of flights

Coronavirus testing sites in a number of states including New York, Pennsylvania, Connecticut and Maryland have closed, CBS News reports.

Officials say they are monitoring any potential impact of the storm on the delivery of the Pfizer/BioNTech vaccine to hospitals.

"We're following all of that," he said. "We have prepositioned Centres for Disease Control and Prevention people at each place receiving people. This is FedEx, this is UPS express shipping - they know how to deal with snow and bad weather, but we are on it and following it."

New Jersey Governor Phil Murphy warned residents to wear a mask if they help their neighbours shovel snow.

Bob Oravec, a Weather Service meteorologist told the New York Times: "The snowstorm is going to have a huge impact on travel. It will be an issue, but it is not going to be an event that is too long lasting."