It was a slow and treacherous Wednesday morning commute in Calgary after a winter storm dropped almost a third of a metre of snow in parts of the city.

For the latest tweets on road conditions in and around Calgary, see the blog at the bottom of this story.

Since the storm rolled in on Tuesday afternoon, southern parts of the city received 31 centimetres of snow, while northern parts of Calgary got 15 centimetres, Environment Canada's website says.

Southwestern Alberta saw the most snow. The Beaver Mines area west of Pincher Creek got 40 to 60 centimetres and 40 centimetres fell on Castle Mountain.

Okotoks received 35 centimetres of snow and 32 centimetres fell in High River. Kananaskis Country got 15 to 30 centimetres and in Banff only nine centimetres fell.

The snow tapered off late Wednesday morning as the weather system made its way out of the province.

The agency ended its snowfall warning for Calgary and most parts of southern Alberta by about 9 a.m. on Wednesday.

Calgary streets were snow-clogged and the morning commute was slow on Wednesday after a winter storm moved over southern Alberta. (CBC )

Calgary Transit tweeted Wednesday morning that many buses are on detour routes because of the snow.

City crews were out all night working to clear the major routes, including 65 trucks and 20 graders, road maintenance manager Bill Biensch told the Calgary Eyeopener.

A man believed to be in his 20s was killed after an SUV crashed into a pole on Stoney Trail near Highway 22X S.E. on Tuesday. (Mark Matulis/CBC)

"Just leave a little bit earlier so that you arrive at your destination safely," he said.

StrathconaTweedsmuir School in the Okotoks area tweeted that it is closed Wednesday, its access road impassible because of the snow. Edison School in Okotoks is also closed.

Good morning <a href="https://twitter.com/hashtag/YYC?src=hash&ref_src=twsrc%5Etfw">#YYC</a>! Leave some extra time for yourself on the road if you’re coming to the airport today <a href="https://twitter.com/hashtag/yycsnow?src=hash&ref_src=twsrc%5Etfw">#yycsnow</a> —@FlyYYC

2 fatal crashes

Two people were killed in separate crashes Tuesday as the snow accumulated rapidly and visibility was reduced in and around Calgary.

The first crash happened about 3:30 p.m. when an SUV travelling south on Highway 2 rolled near the Crossfield turnoff, just north of Calgary, and landed on its roof.

A 23-year-old female driver was declared deceased at the scene and a 21-year-old female passenger was not injured.

Both women are from Cardston.

Roads in Calgary started to get slippery Tuesday as a storm packing lots of snow moved in over much of southern Alberta. (CBC)

About an hour later, a Ford Escape was travelling on Stoney Trail near Highway 22X when it fishtailed, left the road and hit a pole, police said in a release.

The 19-year-old driver was taken to hospital and later died from his injuries. Three other men who were in the vehicle suffered minor injuries.

It's believed the vehicle was travelling too fast for the road conditions.

​Many collisions in Calgary and area

From 4 p.m. Tuesday until 4 a.m. Wednesday, there were 149 collisions on Calgary roads, 17 involving injuries. And from 8 p.m. Tuesday to 8 a.m. Wednesday there were 60 collisions, seven involving injuries.

RCMP say they've responded to 55 collisions in the southern part of the province — from roughly Olds south — since the snowfall started.

Alberta Motor Association driving instructor Wayne McLachlan says lane definition might be a problem on many routes.

"So I think ... just using good discretion with speed and leaving yourself a safe following distance," he said. "If you're lane changing, do it gently ... so you don't lose control of your vehicle."

City officials said they don't expect to enact a snow route parking ban, however that could change if conditions deteriorate.

​Carmacks maintains provincial roads in the city, including Stoney Trail and Deerfoot Trail. Highway division manager Gary Brooks says they will have crews out 24/7 to keep motorists moving.

City crews work first to clear P1 routes — major commuter roads like Crowchild Trail, Memorial Drive and Macleod Trail — along with applying a de-icing mixture known as beet brine to trouble spots, bridge decks and on- and off-ramps.

Once the P1 routes are cleared, crews begin clearing P2 routes such as Acadia Drive and Kensington Road. But they will return to clearing P1 routes if snow starts falling again.

Homeowners are responsible for clearing snow from sidewalks adjacent to their properties within 24 hours after the snow has stopped.

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