VICTORIA -- Many on Vancouver Island woke up to a rare dusting of snow Thursday morning. But Environment Canada says it’s just the beginning.

A winter storm watch is in effect for much of the island, including Greater Victoria. The weather service says between 15 to 25 centimetres could fall Friday evening through Saturday morning.

The area covered by the storm watch includes southern, western, inland and eastern Vancouver Island.

The Comox Valley RCMP said part of the Inland Island Highway was closed Thursday morning due to "slippery conditions and motor vehicle incidents." Drivers were asked to avoid the area.

Northern Vancouver Island was the only area in the region not under a winter-weather warning Thursday morning.

The Greater Victoria area and southern Gulf Islands also remain under a cold-weather warning with wind chill values ranging from -10 to -25 expected. The cold snap is expected to lift over the weekend with temperatures returning to normal.

“Pacific moisture will begin to collide with the arctic front along Vancouver Island Friday night,” says Environment Canada. “Snow that is forecast to start Friday evening will persist through Saturday morning. It's uncertain at this time how much snow will fall, but computer models are beginning to agree on amounts of 15 to 25 cm.”