Environment Canada is warning that snow currently falling in Toronto could become heavy at times on Wednesday night.

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.

Areas in eastern Ontario could see upwards of 40 centimetres of snow by the afternoon on Thursday, Feb. 13, Environment Canada says.

Winter weather advisories issued earlier this week are being upgraded to warnings ahead of a storm expected to bring up to 40 cm to parts of southern Ontario.

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

Environment Canada has issued a snowfall warning for much of southern Ontario, including the Greater Toronto Area, ahead of a major winter storm set to hit the region on Wednesday.

A Texas low is expected to bring the largest snowfall of the season for Ontario mid week with some regions seeing 30cm of snowfall. Meteorologist Rhythm Reet from The Weather Network breaks down the timing and impacts of the storm.

Environment Canada says much of southern Ontario will see heavy snowfall tonight and some regions could see up to 40 centimetres of snow, while northern Ontario braces for extreme cold temperatures.