Slippery driving conditions are being reported around the GTA as a bout of messy winter weather descends on the city.

Ontario Provincial Police said Sunday evening that there have been more than 260 collisions reported on GTA roads today – more than twice the usual amount.

OPP reminded drivers to slow down when road conditions become slick and also to keep an emergency kit in vehicles as a precaution.

Residents across the GTA and much of the province are being advised to prepare for a significant snowfall that could make for a messy commute Monday morning as well.

A snowfall warning issued by Environment Canada for the Greater Toronto Area and much of southern Ontario Sunday afternoon is advising that a “significant snowfall” could dump around 15 centimetres of snow on much of the region between Sunday afternoon and Monday morning.

The snowfall began Sunday afternoon and is expected to intensify overnight.

“Commuters can expect a slow go of it on Monday morning as roads are expected to be snow-covered or slushy and potentially slippery,” Environment Canada said in its warning. “The only exception may be right along the Lake Ontario shoreline where roads may be wet with temperatures slightly above the freezing mark.”

Drivers, pedestrians urged to be prepared

Sgt. Murray Campbell, a member of Toronto police’s traffic services division, said the snowfall could have a big impact on driving conditions Monday morning.

“We have had a very, very warm fall and into winter now. We’ve had a few snow events come so far but it sounds like this one is going to be more of a significant one and drivers, pedestrians and anybody commuting or travelling overnight should be preparing now for what may come,” Murray told CP24 Sunday morning.

“It sounds like the weather may be changing and there may be multiple snow conditions, ice conditions, slush conditions by Monday morning that we should be prepared for.”

Murray added that drivers should make sure that their vehicles are ready for winter.

“If you have snow tires they should be on your vehicle by now,” he said.

“Make sure you fill up your winter washer fluids so that you can see clearly when slush and snow is flying up.”

Pedestrians should also prepare for messy walking conditions in the next 24 hours, Murray said.

“The plows are going to be out tomorrow. Be aware that they are going to be plowing snow up on to the side of the sidewalks and you are going to have to navigate your way,” he added.

“Be aware of your surroundings. Keep a good lookout for vehicles that are travelling. They can’t slow down as quickly as they normally could on dry weather. You have to be aware of that and protect yourself.”

Environment Canada said the messy weather could have a big impact on the morning rush.

“Be prepared to adjust your driving with changing road conditions. There may be a significant impact on rush hour traffic in urban areas,” the agency’s warning said.

City crews preparing for messy conditions

Hector Moreno, road operations manager for the City of Toronto, said road crews will be out in full force tonight and tomorrow.

"Overnight last night and into this morning we had all of our anti-icing trucks applying brine on the elevated highways, bridge decks, high-collision intersections as well as some of our ramps and hill bridges right through the night," he said Sunday.

"That is primarily as a preparation for what is to come later on."

Moreno added that plows will likely hit the major roads and highways shortly before midnight tonight.

[Click here to see the city's plow-tracking map]

The city has 600 snow plows, 300 sidewalk plows and 200 salters available.

"Motorists are advised to take significant time to get to where they need to be and of course, use public transit wherever possible," Moreno said.

The city is also asking people to avoid parking on busy streets that serve as major transit routes.

Transit, air travel could be impacted

Metrolinx said Sunday that severe weather planning was in effect for GO Transit and the UP Express airport rail.

Go Transit reported delays of an up to an hour on some routes because of weather Sunday night. GO said the Route 16 GO bus will not operate Monday because of weather conditions, but advised people to use the Route 18 bus and Lakeshore West GO train instead.

The TTC has not reported any serious weather-related problems so far.

Toronto Pearson International Airport advised air travelers Sunday to check their flight status before heading to the airport. Pearson’s website indicated dozens of cancelled arrivals and departures Sunday evening.

Porter airlines also advised travelers to check their flight status online in case of possible delays or cancellations.