Weather Alert National Weather Service. Impacts • Hazardous winter travel conditions on the high passes and Mt. Shasta Region Friday morning. • Winter travel conditions east of the Cascades on Friday especially on Highway 97. • Hazardous winter travel conditions possible on the lower passes on Saturday. Forecast Confidence • Snow and Snow Levels: Medium to high except less confidence Saturday due to very low and variable snow levels. Timing and Strength • Snow: The heaviest snow rates will be Friday morning when the Cascades, Siskiyous, and Mt. Shasta Region experience around one-inch per hour snowfall. Snow levels will range from 3000-3500 feet except only around 2500 feet in the Mt. Shasta Region. Interstate 5 will be impacted by heavy snow at Siskiyou Summit and in the Mt. Shasta Region between Dunsmuir and Weed. The Tiller-Trail Highway crest at 3000 feet near the Douglas-Jackson County line may see between 4 and 8 inches of total snow on Friday. Snow showers will lower to around 1000 feet by Saturday morning. Most west side valley snow accumulations will be minimal but variable. There could be significant accumulations in heavier snow showers around Canyon Creek Pass on Saturday. The eastside valleys could see between 3 and 5 inches of snow on Friday but the most impactful snow is expected at the higher elevations of Highway 97. Weather Summary: A strong cold front will move inland across the region on Friday. Colder air behind the front will lower snow showers down to the western valley floors by Saturday morning but the heaviest snow is expected in the mountains on Friday. Some western valleys and lower passes on I-5 could see accumulating snow on Saturday. Christmas Day is looking dry.