VICTORIA -- Winter storm conditions are barrelling down on Vancouver Island, with blowing snow and poor visibility expected for Greater Victoria overnight.

Environment Canada increased the severity of its winter storm warning for Greater Victoria on Friday morning, saying heavy snow is expected to begin before midnight and last through to Saturday morning.

Approximately 15 to 25 centimetres of snow is expected for southern, eastern and western Vancouver Island, with higher accumulations around the Strait of Juan de Fuca. Strong easterly winds will make for near-zero visibility at times, according to the weather service.

"Surfaces such as highways, roads, walkways and parking lots may become difficult to navigate due to accumulating snow," Environment Canada warned.

Moisture approaching from the west is expected to collide with an Arctic cold front, creating near-perfect storm conditions over the island.

BC Transit is letting Greater Victoria residents know that service disruptions are expected this weekend.

"Service will stop at midnight as heavy snowfall is expected throughout the system," said BC Transit in a social media post Friday.

"Service detours and interruptions are expected to continue on Saturday morning."

The Malahat highway between Goldstream and Mill Bay will become treacherous Friday night into Saturday morning, due to accumulating snow and poor visibility.

Much of B.C. remains under a cold-weather warning as an outflow of Arctic air has plunged temperatures well below seasonal values.

The latest B.C. highway conditions are available here.