Toronto's Pearson International Airport says that some flights from Toronto to the U.S. East Coast have been cancelled due to a massive winter storm that the U.S. National Weather Service believes could rank near the top 10 to ever hit the region.

Some Canadian travellers have received word from their airlines that flights up to two days from now have already been cancelled due to the weather forecast.

Five U.S. states have declared a state of emergency and Washington, D.C., is supposed to be buried under more than 60 centimetres of snow.

The U.S. National Weather Service says the snowfall is expected to continue from late Friday into Sunday and could easily cause more than $1 billion in damage, potentially paralyzing parts of the U.S. East Coast. 

Around three per cent of incoming flights and four per cent of outgoing flights have been cancelled, according to GTAA spokeswoman Shabeen Hanifa.

"That can be for a number of reasons including the weather out on the Eastern seaboard," she said. "The best thing passengers can do is check their flight times with their airline before coming to the airport."  

Passengers can also check the status of their flight through the Toronto Pearson website.