While the recent rains have in no way put an end to California’s severe drought, they have pushed the Tuolumne River watershed accumulation totals ahead of its yearly pace — and more help is on the way, according to information published by Turlock Irrigation District.
Barely three months into the new water year — TID’s water year starts on Sept. 1 and runs through Aug. 31 — the numbers are positive, according to a TID hydrology report.
After receiving 1.5 inches of precipitation in September and less than a tenth of an inch in October, there was 4.07 inches in November and, as of Monday, 3.29 inches in December.
That’s a year-to-date total of 8.92 inches.
“Historically, through December we average 12.56 inches,” said TID communications specialist Brandon McMillan, who pointed out that, December, January and February tend to be the wettest months of the year.
TID’s 16-day forecast (starting on Dec. 5) calls for 5 more inches of precipitation through the 21st. The National Weather Service has issued a winter storm advisory through Monday for the Sierra Nevada at altitudes of 3,500 feet and above.
The U.S. Forest Service activated a backcountry avalanche watch late Friday in the central Sierra including Tahoe and warned of higher avalanche danger Saturday into Sunday.
“A winter storm with gale force winds, high intensity snowfall and feet of new snow accumulation may result in widespread avalanche activity in the mountains,” the Forest Service Sierra Avalanche Center said Friday.
As much as 18 to 28 inches (45 to 71 centimeters) of snow is forecast through the weekend at lake level, and up to 4 feet (1.2 meters) at elevations above 7,000 feet (2,133 meters) with 50 mph (80 kph) winds and gusts up to 100 mph (160 kph).
Authorities urged motorists to stay off mountain roads in the Sierra through the weekend.
“You could be stuck in your vehicle for many hours,” the weather service in Reno warned.
On the Sierra's eastern slope, a winter weather advisory runs from 10 p.m. Saturday to 10 a.m. for Reno, Sparks and Carson City, with snow accumulations of 1 to 3 inches (2.5-7.5 cm) on valley floors and up to 8 inches (20 cm) above 5,000 feet (1,524 meters).
The additional precipitation would move the watershed’s year-to-date total to about 14 inches, with 10 more days remaining in December — meaning the watershed would be ahead of its average yearly pace heading into 2023.
“By all accounts, that’s good news,” said McMillan. “It doesn’t mean that it can’t change. Last year, we had a very wet October and strong December, then it was bone dry. It can definitely turn, but what we’ve received so far is definitely good news.”
The Tuolumne River watershed is a 1,500-square-mile area that originates on the crest of the Sierra Nevada. Water there tumbles down rocky mountainsides and through glacially carved valleys on its way to the Central Valley.
— The Associated Press contributed to this report.