Storms expected to bring rain, snow this week

A significant winter storm is expected to bring rain to the Mother Lode foothills, gusting winds, and heavy mountain snow to the Central Sierra from Wednesday to Friday, and a second storm system could bring more snow to the mountains Saturday into Sunday.

Overnight lows for the Sonora area are expected around 34 Monday night, 36 Tuesday night, and rising to 40 degrees as the first storm moves in Wednesday night. Overnight lows in the mid-30s

are expected Thursday and Friday nights.

Snow levels could drop as low as 2,500 to 3,000 feet in Calaveras and Tuolumne counties.

“It’s a colder winter storm from the Gulf of Alaska,” Katrina Hand, a National Weather Service meteorologist in Sacramento, said in a phone interview Monday afternoon. “We’re expecting precipitation starting Wednesday night through Friday morning and then a brief break with possible showery activity followed by another system this weekend with more snow in the mountains.”

The heaviest rain and snow is expected Wednesday to Friday, rain in the foothills and heavy snow in the mountains, Hand emphasized. Strong, gusting winds out of the south-southwest are possible Thursday. Maximum winds of 25 to 30 mph are possible Thursday in the Sonora area.

Ebbetts Pass on Highway 4 and Sonora Pass on Highway 108 could get 4 to 5 feet of new snow by Sunday. Tioga Pass on Highway 120 could get 3 to 4 feet of new snow by Sunday. Sonora and other foothills towns could get 3 to 4 inches of rain by Sunday, and lower elevations in Yosemite could get 4 to 5 inches of rain by Sunday.

There’s also a freeze watch Tuesday night to Wednesday morning for sub-freezing temperatures from 28 to 32 degrees in valley communities south and southwest of Tuolumne County.

As of Monday, the principal watersheds in the Central Sierra, including the Stanislaus and Tuolumne river canyons in Calaveras and Tuolumne counties, had received 4 inches of precipitation so far in the water year that began Oct. 1. October was dry. All the measurable rain and snow over the past two months came in November. The total of 4 inches as of Monday equated to 75% of average for the date Nov. 28.

The approaching storms are likely to add to the state’s invaluable snowpack and future water supply. But in spite of weather forecasts Monday, the U.S. Bureau of Reclamation urged Central Valley Project water contractors for municipal and industrial uses to begin planning for extremely limited water supply conditions in 2023.

Even with early winter season storms this month, drought conditions are continuing in California. Conservative planning efforts will help better manage limited water resources if conditions remain dry, and California moves into a fourth consecutive drought year, the federal agency said.

As of Nov. 22, the foothills of Calaveras and Tuolumne counties were in the most dire drought category, exceptional drought, most of the rest of both counties were in extreme drought, and the highest, eastern-most edges of both counties were in severe drought, according to scientists with the U.S. Drought Monitor. Eighty-five percent of the Golden State was in severe drought or worse.