Delays and cancellations disrupted flights in and out of Toronto this morning as the U.S. East Coast was hammered by a massive blizzard. 

More than 50 of Saturday's flights out of Pearson International Airport — mostly to eastern seaboard destinations including New York, Washington and Philadelphia — were cancelled, and roughly a dozen others were delayed.

Roughly the same number of arrivals were also cancelled. 

Travellers were advised to check their flight's status before leaving for the airport. 

Cities across the northeastern U.S. are under blizzard watches and seven states declared states of emergency because of the weekend storm that is expected to drop at at least 60 centimetres in some areas. 

Forecasters have also predicted more than a centimetre of ice accumulation in the Carolinas, and potentially serious coastal flooding in the mid-Atlantic. 

Meanwhile, Porter Airlines says it is still dealing with software problems that caused more than 15 flight cancellations out of Billy Bishop Airport on Friday. 

The "prolonged systems outage" continues to affect Porter's reservations and other systems, the airline said Saturday in a statement.

The airline says passengers whose flights were cancelled on Friday will be rebooked on flights today, provided seats are available. 

Some Porter flights to the U.S. East Coast have also been cancelled. 

Air Canada flights from the downtown island airport are not affected by the computer issues.