With Halloween more than a week away, the National Weather Service (NWS) is already warning of snow in the mountains starting on Wednesday, Oct. 21, and continuing through Thursday, Oct. 22.
Three mountain passes are closing on Wednesday, and forecasters expect slick road conditions during both the Wednesday evening and Thursday morning commutes.
California Looking at Up to 10 Inches of Snow
The NWS in Reno has issued a winter weather advisory for Mono County, Calif., above 8,000 feet, including Mammoth Lakes, Lee Vining, Bridgeport and Coleville.
“Snow accumulations of 4 to 8 inches with up to 10 inches along the highest mountain peaks. Winds gusting as high as 35 mph,” the NWS stated on Tuesday, Oct. 20. It added that “the hazardous conditions will impact the Wednesday evening and Thursday morning commutes.” In a graphic shared on X, the office rates the storm 3 out of 5, or moderate.
On the other side of the range, the NWS in Hanford is also warning of snow in Yosemite, Kings Canyon and Sequoia national parks. “There is an 80% chance of 4 inches or more of snow along the Tioga Pass and highway 120,” the office shared in its advisory.
Mountain Passes Closing Before the Snow Arrives
According to a report from myMotherLode, Sonora Pass on Highway 108 and Ebbetts Pass on Highway 4 are closing on Wednesday morning, with Caltrans planning to “keep both passes in intermittent closure status” until crews can check the roads.
Tioga Road through Yosemite National Park is also closing on Wednesday evening “due to the potential for wet, icy, slippery roadway conditions,” the outlet adds. Park crews will need to check it for damage and debris once the snow ends, and Caltrans told KOLO that “the roadways will be reassessed after the storm passes.” No reopening date has been given for any of the three.
Highest Peaks Could See Even More Snow, Forecasters Say
According to a report from Unofficial Networks, NOAA’s Weather Prediction Center gives the southern Sierra a 40% to 70% chance of more than 8 inches of snow above 10,000 feet by Thursday night, and a 10% to 30% chance of snowfall exceeding a foot.
Safety Tips for Heading Into the Mountains
As for safety tips, the NWS in Reno says, “Please use caution if you need to travel through these areas and check with Caltrans for the latest road conditions!” Its graphic goes a step further and suggests drivers consider delaying their travel plans. With hazardous conditions expected to affect the Wednesday evening and Thursday morning commutes, anyone who can wait until the advisories end on Thursday may want to do just that.
“Always carry chains,” Caltrans advises in its winter driving tips, adding, “Make sure they are the proper size for your tires and are in working order.” It also notes that “bridge decks and shady spots can be icy when other areas are not.”
The NWS in Hanford also advises anyone heading outside to “watch your first few steps taken on stairs, sidewalks, and driveways,” since those surfaces could be icy.
If you’re planning a visit to Yosemite this week, the park’s current conditions page notes that Hetch Hetchy Road is “closed when it is snowing or snow is forecast overnight,” and that overnight parking isn’t allowed on Tioga Road or Glacier Point Road, including in all parking lots accessible from either road.
