Airlines are warning that travel to and from Central Canada may be affected by a winter storm sweeping in from the west.

The blizzard conditions may cause delays to flights into and out of airports in Toronto, Ottawa and Montreal on Wednesday and Thursday, Air Canada and WestJet said.

Air Canada had delayed or cancelled more than 160 of its flights for the day -- or about 26 per cent -- by late Wednesday afternoon, according to tracking service FlightAware.

WestJet said it cancelled 37 flights at the Toronto, London, and Kitchener-Waterloo airports on Wednesday and Thursday due to the extreme weather. More than 130 of its Wednesday flights, or 29 per cent, were delayed, according to FlightAware.

The tracker said carriers have already cancelled nearly 2,500 flights in the United States as of early Wednesday afternoon, threatening to snarl trips and connecting flights for Canadians as well.

Environment Canada warns heavy snow will hit a swath of southern Ontario starting in the late afternoon, followed by ice pellets and freezing rain overnight.

It forecasts snowfall will total 10 to 15 centimetres with winds gusting at 50 to 70 kilometres per hour as the low-pressure system advances from the American southwest.

"We are monitoring the weather and we have made some schedule adjustments in anticipation of the storm, and this is ongoing as the situation evolves," Air Canada spokesman Peter Fitzpatrick said in an email, noting that customers will be rebooked or can opt for a refund.

Jazz Aviation, which operates regional flights for Air Canada Express, has also cancelled 75 of its Wednesday flights, or 16 per cent, according to FlightAware.

WestJet said in an email all guests would be rebooked on the first available flight within 48 hours.

This report by The Canadian Press was first published Feb. 22, 2023.