From school closures to messy roads and cancelled flights – a major winter storm made for a treacherous Tuesday in Toronto and much of southern Ontario.

The storm started early in the morning and picked up rapidly, dropping a biting mix of ice pellets, snow flurries and freezing rain on much of the region.

By the evening, about 15 centimetres of snow and ice accumulated in some areas.

“Snow – at times heavy – continues over the region. Strong easterly winds gusting near 70 km/h will result in sudden and significantly reduced visibility to blowing snow,” Environment Canada said in a weather advisory issued in the morning. The agency currently has the region under a winter storm warning.

An additional five centimetres of snow is expected Tuesday night.

Snow plowing and salting will stretch overnight

Salting started on city roads at around 7:45 a.m. Crews transitioned to plowing main arterial roadways and expressways shortly before noon.

Myles Currie, the city’s director of road operation, cautioned residents about their response, saying that it may take until Wednesday morning before plows make it to all side streets.

“There’s a possibility that we won’t be getting to our local side streets, our neighbourhood streets until the end of the storm, which is probably going to be around midnight,” he said.

“We ask that you wait until at least tomorrow morning at 6 a.m. if you think your street hasn’t been plowed. Just give crews a chance to get around the city.”

Residents can assist crews by not parking on roadways, especially those that double as streetcar corridors, to allow for optimal road clearing, Currie said.

Salt trucks returned to the roadways Tuesday evening as the snow transitioned to freezing rain.

“It does change the game plan slightly,” said Mark Mills, the city’s superintendent of road operations, on Tuesday afternoon. “It looks like the transition from snow to rain has happened so we are going to have to be very diligent in our patrolling right now.”

“But we will continue to plow.”

The city worked in conjunction with the TTC and Toronto police to monitor, identify and respond to vehicles that obstructed right of ways and impeded road clearing crews.

“I’ve asked our traffic management centre to focus their traffic cameras on corridors with streetcars so we can identify vehicles blocking and respond as quickly as possible,” Currie said.

“To be more efficient, we have the TTC, parking enforcement and tow trucks working in unison.”

[Full weather forecast can be found here]

Torontonians were also being warned about extreme cold temperatures, as wind chill values hit -19 in the morning and was expected to linger through the afternoon.

The national weather agency urged people living in affected areas to postpone non-essential travel, if possible, as conditions were expected to be “hazardous.”

TDSB, TCDSB closes all schools

School boards in Toronto and many parts of the GTA took heed of that warning, prompting a snow day for thousands of students.

[Full list of bus cancellations across the GTA]

In a rare move, both the Toronto District School Board and the Toronto Catholic District School Board closed all schools in anticipation of the messy winter storm.

The event marked the first time in 8 years the TDSB closed all of its schools for weather.

TDSB spokesperson Ryan Bird said, after reviewing the forecast, the board decided it didn’t want to take any chances.

“We strive to keep our schools open,” Bird said.

“But we have to weigh the safety of our staff and students versus the obvious inconvenience of having childcares closed and today, based purely on the forecast, we decided that that forecast was concerning enough to have to close down our sites.”

The board will decide early Wednesday morning whether schools will remain closed and buses cancelled.

A number of other school boards and school bus services in the GTA made the same decision, including public and catholic schools in Peel and Halton regions. Others, such as York and Durham, have chosen to stay open. However, bus routes in those districts have been cancelled.

Programs run by the City of Toronto, including indoor recreation and aquatic programs, were cancelled at facilities as of noon. Outdoor recreation programs have been cancelled for the day, as well as after-school programs.

Mayor says city prepared for storm

Tuesday morning, Mayor John Tory said most city services will proceed as normal today. Non-essential city services closed at 2 p.m.

Despite an influx of complaints about snow removal services following a brutal late-January storm, Tory said he was confident the city would be able to handle this bout of weather.

“I don’t think you’ll see a big difference. We have established practices that work quite well,” he said.

“I think today will be dealt with a full armada of trucks and salters and plows and we will do the very best we can. I know our staff is up to that job.”

Tory called for a review of winter operations in the city earlier this month, in light of residents’ complaints.

The review will look at “longer term questions,” he said Tuesday, including the threshold for declaring a major snow event and best practices for dealing with certain quantities of accumulation.

“I think those things merit being looked at from time to time, so we’re going to do that,” he said.

“I hope if we have the cooperation of people who act responsibly and safely and not drive their cars if they don’t have to, and frankly stay home… A lot of kids are staying home from school today. I hope everybody acts that way and we’ll get through this fine.”

“It’s a snow storm. We’ve had this before and we’ll have them again.”

Many GTA university and college campuses closed

The University of Toronto - Mississauga is closed.

University of Toronto – Scarborough is closed

York University is closed and all university operations suspended. Classes scheduled for today are cancelled and exams postponed.

Ryerson University is closed today.

All Humber College campuses and the University of Guelph-Humber are closed today.

Seneca College is closed

Centennial College is closed, as are the college’s child care centres

George Brown College is closed

All Georgian College campuses are closed and classes are cancelled.

OCAD University has cancelled all classes and activities.

Flights and transit impacted

Travellers who are scheduled to fly today should also prepare for cancellations and heavy delays.

As of 6 p.m., 34 per cent of all arriving and departing flights at Toronto Pearson International Airport had been cancelled.

Passengers are encouraged to plan accordingly and check in with their airline.

“The combination of heavy snow and snow pellets and the high winds will result in these kinds of delays and cancellations by airlines,” Maria Ganogiannis with the Greater Toronto Airport Authority said Tuesday morning.

“We have extra crews on hand and snow clearing equipment ready and positioned to begin the snow removal process in between arrival and departures.”

As for transit, subway service on the Scarborough RT was suspended Tuesday evening due to mechanical problems. Around 8 p.m., the TTC said that all streetcar routes were impacted by the weather.

"Customers will experience delays on all lines due to freezing rain on overhead wires," the TTC said on social media.

Metrolinx had their “winter activation plan” in place in anticipation of messy morning and afternoon commutes.

A check-over of platforms and vehicles was conducted on Monday, and additional staffing has been added.

“Weather conditions are affecting service on the Lakeshore East line. Trains will run every 30 minutes to "help ensure reliability," GO Transit wrote on Twitter.

The TTC encouraged its riders to plan their commute with extra time.

De-icing has been carried out on some routes and trains and extra staff are on standby.

The TTC’s chief operating officer, Jim Ross, said the morning commute was relatively unscathed by the winter weather.

“We did overstaff by 60 buses just as insurance, because we didn’t know which way the morning was going to go,” Ross said. “We’ve been over servicing busy routes.”

“We ran service trains all night long to prepare the power rail, we have power rail heating,” he said of the Scarborough RT.

“We had one mechanical issue on a train that is not weather related, otherwise it is regular scheduled service.”

Other closures due to weather: