VANCOUVER -- Environment Canada issued a snowfall warning for the stretch between Hope and Merritt, where forecasters predict up to 25 centimetres could accumulate. 

"A moist and unstable airmass will continue to give flurries to the Coquihalla Highway, Hope to Merritt route today," the weather warning says. 

"Rapidly accumulating snow could make travel difficult over some locations. Visibility may be suddenly reduced at times in heavy snow."

Environment Canada says there will be some brief periods of heavier snow. By Friday afternoon, the snow level is expected to rise from 700 metres to about 1,000 metres.

"Weather in the mountains can change suddenly resulting in hazardous driving conditions," the warning says. 

Winter tires and chains are now required on many B.C. highway routes. Those rules came into effect on Oct. 1, and will stay in place until next spring.  

In Vancouver, temperatures are expected to reach 9 C over the weekend and dip to 4 C on Saturday. While it'll be mostly rainy, Saturday could see a mix of sun and cloud.