Heavy snow and high winds hammered the Sea to Sky Highway Tuesday, making for treacherous driving conditions on the way to Whistler.

The precipitation began early in the afternoon and picked up in the hours that followed, especially through Squamish and beyond.

"We're seeing really strong outflow winds and that's maintaining that cold air in the Howe Sound corridor and up towards Whistler," Environment Canada meteorologist Matt McDonald told CTV News.

Up to 20 centimetres could fall by Wednesday morning before the snow turns into rain.

Mounties are urging drivers to be cautious on the highway, reminding motorists they could slide off the road even if they have good winter tires.

"We actually find that the majority of people are compliant with winter tires, but if you're hitting patches of black ice and slush, you're going to go off the road even though you have winter tires," Cpl. Sascha Banks said. "So it's a matter of really slowing down and making sure that you're aware of the conditions that you're in."

The situation was exacerbated by high winds in the area that blew snow and reduced visibility.

Powerful gusts also forced the closure of the Sea to Sky Gondola, a popular tourist attraction near Squamish.

"We take the weather and wind warnings very seriously when Environment Canada puts out a warning, and earlier on this afternoon that wind had definitely picked up as anticipated," said Ken Bailey, the attraction's director of business development.

Over on Vancouver Island, the same Pacific frontal system delivered a winter wallop in Comox Valley and the surrounding areas.

With files from CTV Vancouver's Ben Miljure