Sunshine was expected to fade away Friday as the first of a series of cool, wet storms moved closer to the Mother Lode and the Central Sierra, with a winter storm warning in effect from 6 p.m. Friday to 8 a.m. Sunday for 1 to 2 feet of snow possible above 5,000-foot elevations.
The approaching storm could bring 2 to 3 inches of rain in the Sonora area and Yosemite Valley by Sunday, with chances of afternoon thunderstorms Friday and Saturday. There’s also potential for more storms bringing more rain, mountain snow, and gusting winds to Calaveras and Tuolumne counties later next week and next weekend.
A low-pressure system was tapping into atmospheric river moisture off the California-Oregon coast before noon Friday and was expected to begin bringing rain and mountain snow to inland central California by Friday evening, Chelsea Peters, a National Weather Service meteorologist in Sacramento, said in a phone interview Friday morning.
The winter storm warning area Friday included Avery and Arnold on Highway 4, and Twain Harte and Mi-Wuk Village on Highway 108. It did not include Groveland, Pine Mountain Lake, and Buck Meadows on Highway 120.
There are chances for 24 to 30 inches of snow at Ebbetts Pass on Highway 4 and 18 to 24 in
ches at Sonora Pass on Highway 108. Snow levels, expected around 7,000 feet on Friday, could lower to 3,500 feet by early Sunday. Winds of 15 to 20 miles per hour were expected through Saturday.
The storms expected next week and next weekend appeared to be two fairly distinct systems as of Friday, Peters said. Timing and details for extended forecasts beyond this weekend remained uncertain.
As of Friday morning, regional Central Sierra precipitation remained at 24.5 inches for the Stanislaus River and Tuolumne River watersheds since the current water year began Oct. 1, equivalent to 78% of average for the date March 22.
Instruments monitored by the state showed current snow depths of 71 inches at Ebbetts Pass, 64 inches at Sonora Pass, 89.9 inches at Tioga Pass, 65.1 inches at Dana Meadows, and 82 inches at the University of California, Berkeley, Central Sierra Snow Lab in Soda Springs, Nevada County, as of Friday.
The statewide average snow water equivalent Friday was 24.9 inches, 98% of normal for the date March 22. In the Central Sierra, the average snow water equivalent was 24.8 inches, equal to 95% of normal for March 22 and 93% of the April 1 average.
Principal reservoirs in Central Sierra watersheds, including Camanche, Pardee, New Melones, Don Pedro, Cherry, and Hetch Hetchy, remained more than 80% full as of Friday.
Scientists with the U.S. Drought Monitor said 4.54% of the Golden State — comprising small pockets of land near the Oregon, Nevada, and Arizona borders — was abnormally dry as of Thursday, and 100% of the state remained drought-free.
