Drivers are being urged to plan for a sloppy and delayed Wednesday morning commute as Toronto braces for another winter storm expected to roll into southwestern Ontario Tuesday night.

Environment Canada issued a heavy snowfall warning for most of the GTA, including Toronto, as a storm tracking aross the U.S. Midwest makes it way north this afternoon. 

The storm is expected to be a messy one, starting with a mixture of rain and snow, followed by more snowfall as the temperature drops overnight.

The snow will be especially heavy during the overnight hours into Wednesday, Environment Canada says, with peak snowfall rates pegged at two to five centimetres per hour during the most intense part of the weather system.

Total snowfall amounts are expected to reach 15 to 20 centimetres by noon Wednesday, although the agency says amounts near the Lake Ontario shore will be smaller.

Drivers are being advised to move slowly, take extra time and follow other vehicles from a further distance as visibility will be reduced and untreated roads become snow-covered and slippery.

Airlines are encouraging passengers to check their flight status ahead of their trip to the airport.

Toronto learns its lesson

Crews have been salting Toronto roads since Monday night, but the anticipated rain could wash away some of the brine. Nevertheless, salt trucks remain on standby.

Peter Noehammer, director of Toronto's Transportation Services, says crews are strategizing on how best to tackle the snowfall head-on.

“We’re looking at ways of improving the way we can clear snow from areas next to transit lines, streetcar tracks in particular,” he said.

Crews want to avoid a similar outcome to a massive storm that hit Toronto in early February. That winter wallop crippled movement on roads and ultimately triggered a $5-million cleanup.

Then, Toronto was criticized for not declaring a snow emergency, which would have given the city authority to tow cars parked on snow routes so that cleanup crews could plow the snow right up to the curb.

The snow bylaw is now being reviewed by staff, but Noehammer said they’ll act on it if conditions call for it this week.

“If it does turn out to be 25 or 30 centimetres again, and certainly that is on the high side of what they’re currently predicting, we’ll look into measures like that to help us out and to clear those streets faster,” he said.

The wintry weather system moving through Midwest has forced highway closures, cut power to thousands and is being blamed for at least two deaths.

With a report from CTV Toronto’s Natalie Johnson and with files from The Associated Press