More on the way
Strong storm will bring rain, snow, wind to Mother Lode
A slow-moving winter storm exiting the Mother Lode and the Central Sierra on Thursday afternoon brought 24-hour rain totals above 1 inch near New Melones and Don Pedro reservoirs, along with overnight snow to Long Barn and the upper Highway 108 corridor.
However, forecasters are predicting a stronger, multiday storm will move into the area this weekend and bring more rain, snow and winds into next week.
The approaching storm system is another colder system coming out of the Gulf of Alaska that’s expected to arrive late Saturday or early Sunday and last through Tuesday or early Wednesday, according to Katrina Hand, a National Weather Service meteorologist in Sacramento.
“Starting late Saturday, it’s going to slow down and last through Wednesday,” she said, emphasizing that specifics for the approaching storm were still taking shape as forecasters attempt to predict what will happen almost a week out.
A storm system in late October that brought recordbreaking rains to Sonora and other Central Sierra Nevada locations was an atmospheric river and warmer than the approaching system, Hand said.
Potential snow levels this weekend and early next week were uncertain as of Thursday afternoon.
Hand said communities in Calaveras and Tuolumne counties at lower elevations could receive 3 to 4 inches of rain through Tuesday.
Forecasts for the approaching storm showed the potential for 5 to 6-plus feet of new snow at Ebbetts and Sonora passes, as well as 4 to 5 feet at Tioga Pass.
“It could change,” Hand said. “Wednesday is pretty far out for us.”
Ebbetts Pass on Highway 4 and Sonora Pass on Highway 108 were temporarily closed earlier this week in advance of the Wednesday-thursday storm and remained closed as of Thursday afternoon.
Caltrans officials said the agency would evaluate the storm’s impact on the passes and make a decision on whether to declare them closed for the season.
Tioga Pass on Highway 120 in Yosemite National Park hasn’t reopened since the previous storms in late October and remained closed as of Thursday.
As of 1 p.m. Thursday, rain totals for the storm that began Wednesday evening included .74 of an inch at Copperopolis; .76 inch at Telegraph Hill northeast of Sonora; 1.01 inches near Columbia; 1.14 inches east of Jamestown; 1.17 inches near the North Fork Tuolumne River; and .79 inch east of Groveland.
The exiting storm was moving southeast toward Death Valley and Las Vegas and leaving colder condi
tions in its wake.
A winter weather advisory for the Central Sierra above 5,000 feet was set to expire at 4 p.m. Thursday, while a frost advisory was issued for the Sierra foothills and Central Valley from 2 to 10 a.m. Friday.
Overnight lows in Sonora could dip to 29 degrees Fahr
enheit early Friday and 31 early Saturday.
Storms this week and next are expected to help boost water supply for Tuolumne Utilities District, which provides water and wastewater services to about 44,000 Tuolumne County residents.
“It’s too early in winter to predict how this storm system will impact overall drought conditions in the region, but it definitely will help,” TUD spokeswoman Lisa Westbrook said Thursday afternoon.
Westbrook said Pinecrest Reservoir held 15,619 acre-feet, or 85% of capacity, while Lyons Reservoir held 2,743 acre-feet, or 50% of capacity, as of Thursday. The district relies on both reservoirs for about 95% of its annual supply of surface water.
The district has been working closely with Pacific Gas and Electric Co. to monitor water supply storage at Pinecrest, which Westbrook said is higher than average for this time of the year.
Other major reservoirs in the Calaveras and Tuolumne counties were holding around half-capacity or less.
New Melones on the Stanislaus River, the fourth-largest capacity reservoir in the state, was 36% full Thursday. Don Pedro on the Tuolumne River, the state’s sixth-largest capacity reservoir, was 50% full.
As of Thursday, the Stanislaus River and Tuolumne River watersheds had received 7.6 inches
of precipitation since the current water year began Oct. 1. That total was 101% of average for the date Dec. 9.
A California drought monitor map, updated Tuesday and released Thursday, remained unchanged from Nov. 30.
The southern and western portions of Calaveras and Tu
olumne counties remained under “exceptional” drought, the most dire category, while the high east edges of both counties were in “extreme” drought, the secondmost dire category.
Drought monitor scientists said in their update this week that the big story across the western U.S. continues to be
poor snowpack conditions across the region and growing concern about water supplies after backto-back dry winter seasons in California.