Calgary under a snowfall warning as heavy, wet snow blankets the city

A snowfall warning issued for the foothills Wednesday was expanded to include the City of Calgary and areas north.

According to Environment and Climate Change Canada (ECCC) totals of 15 to 30 centimetres are possible over this multi-day snow event.

A low complex system situated over the Pacific Northwest will drive steady moisture into Alberta via the southern border in waves – with precipitation rates quite high at times.

As expected the precipitation initially started as rain on Wednesday before transitioning to a rain-snow mix and finally heavy, wet snow around 4 a.m. Thursday.

Warmer surface temperatures on roads and sidewalks allowed most of that initial snow to melt on contact, however vehicles that were parked outside overnight had a build-up of slushy, wet snow.

A stronger north wind at the surface complicated matters by amplifying visibility issues, and by 8 a.m. area highways were starting to show some slushy accumulations, prompting 511 Alberta to evaluate highways west and south of Calgary as having winter driving conditions.

With daytime highs expected to remain around freezing for most of the day Thursday and Friday and north winds remaining a factor for Thursday, untreated roads and sidewalks and vulnerable surfaces like corners, intersections, ramps and bridge decks will likely become slick.

Surfaces like wooden decks and patios and grass will also become slicker throughout the day.

There will be very little sunshine until at least Sunday, and daytime highs are expected to remain below seasonal until then.

Areas in the southern foothills are likely to receive the highest accumulations due to an upsloping component – as counter clockwise rotation around the lows pushes moisture back up against the Rockies.

In some communities there will be brief periods of rain mixed in with snow.

For the latest weather advisories from ECCC click here. 511 Alberta highway conditions can be found here, and click here for the latest on B.C. roads