A major winter storm disrupted travel plans, closed schools and shuttered city services across Ontario, Quebec and the Atlantic provinces Thursday, as communities dug out from a wintry cocktail that brought upwards of 20 centimetres of snow.

Roads across the region are snow covered and slippery, with reduced visibility. All schools in the Montréal region, including those off-island, as well as CEGEPS and Universities, are closed today.

A large portion of Ontario, from the Temiskaming-Temagami area in the north to the Sarnia area in the south, is under a snowfall warning, as is the southern half of Quebec

A huge winter storm is expected to descend across parts of Ontario and Quebec later on Wednesday and quickly spread across Atlantic Canada over the next two days, prompting Environment Canada to issue a flurry of weather warnings.

Snow began falling overnight in Montreal, and was expected to continue until midday and gradually ease. Flights were cancelled and delayed at the airports in Montreal and Quebec City on Thursday, and the province's transport agency warned of dangerous road conditions,