Dozens of flights into and out of Toronto have been cancelled as a result of a heavy winter storm hitting the northern U.S.

A nor'easter is expected to bring heavy snow, powerful winds and flooding to a stretch of the U.S. Northeast from Maine to Virginia.

Environment Canada has issued its own warnings, from the west coast of Newfoundland to Quebec's border with Ontario.

Some parts of the Maritimes could be hit with between 25 and 30 centimetres of snow. South of the border, snow accumulation could be up to 60 centimetres.

As a result of the storm system, several dozen flights scheduled to arrive at, or depart from Toronto's Pearson International Airport have been cancelled.

As of 12:30 p.m. Monday afternoon, 37 flights that were meant to arrive in the city had been cancelled, approximately 4.8 per cent of the total arrivals. According to Pearson’s website, 50 departing flights, or 6.7 per cent, were cancelled.

Most of the affected flights were either to or from the New York area, where 15 to 20 centimetres of snow is in the forecast.

In Toronto, skies were clear Monday morning. However, snow is expected to start in the afternoon. Only one centimetre of snow is expected fall in the city, while parts of southern Ontario may be hit with as much as 15 centimetres.

Burlington, Oakville and Hamilton are expected to be hit the hardest, as snow blows across frozen parts of Lake Ontario.