The National Weather Service has issued a winter storm watch for Yosemite and large swaths of the southern Sierra Nevada, warning of heavy snow, near-whiteout conditions and wind gusts up to 50 mph beginning Friday evening and lasting through Sunday night. The watch, issued by NWS Hanford at 2:50 p.m. Wednesday, is in effect from 5 p.m. Friday until 11 p.m. Sunday, April 12.
Forecasters said heavy snow could make travel hazardous and may force closures or delays on mountain roads and at trailheads. “Roads, and especially bridges and overpasses, will likely become slick and hazardous. Visibilities may drop below 1/4 mile due to falling and blowing snow,” the NWS warned, adding that the combination of strong winds and heavy snow could down tree limbs and power lines, producing sporadic outages. Whiteout conditions are possible and may create life-threatening travel situations.
The watch covers Yosemite and adjoining high-country areas including the Upper San Joaquin River corridor, Kaiser to Rodgers Ridge, Kings Canyon and Sequoia national parks, and the south end of the Upper Sierra. Park managers and county authorities have been urged to monitor conditions closely and to warn visitors and residents to postpone nonessential travel until the storm passes.
Local emergency services and the NWS stressed personal preparedness. Recommended precautions include dressing in multiple layers, covering exposed skin to reduce frostbite and hypothermia risk, and ensuring vehicles are winterized and stocked with supplies such as a shovel, jumper cables, blankets, food, water and a flashlight. The NWS advised drivers to leave extra travel time, avoid sudden braking or acceleration, and be cautious on hills and bridges. If stranded, people should stay with their vehicle, notify someone of their location and signal for help.
County and municipal agencies in the Bay Area published information about warming centers and winter shelters for people experiencing homelessness or in need of refuge from the cold. San Jose is operating its Overnight Warming Location program, Alameda County has a posted list of winter shelters through its Health Care for the Homeless program, San Mateo County directs residents to local Core Service Agencies for access to the Inclement Weather Program, Contra Costa County refers callers to 211 for emergency shelter listings, and Solano County maintains a list of centers open during extreme weather.
The late-season storm arrives amid broader meteorological discussion about Pacific conditions that can influence spring and summer weather patterns. Forecasters caution that while large-scale factors such as tropical Pacific variability — including the potential development of El Niño later this year — can affect storm tracks, the specific impacts of any one system are best judged by short-range models and local forecasts. Travelers and recreationists planning to visit mountain areas this weekend should check the latest updates from the National Weather Service Hanford office and local park authorities before heading out.