Rain, snow coming this weekend as Northern California wrestles with drought-like weather

Northern California’s wet weekend marks the first meaningful rainstorm in nearly a month — and will bring a measure of relief with much of the state gripped by drought-like conditions.

Rain began falling in Sacramento Friday afternoon, and the National Weather Service said precipitation would continue intermittently through the weekend. The blast of wintry weather is expected to bring as much as a foot or two of snow in the Sierra Nevada’s highest peaks.

The precipitation won’t be a downpour — the foothills will see 1 to 3 inches of rain by the end of the weekend, with lesser amounts on the Valley floor, said National Weather Service forecaster Bill Rasch.

“Good old medium storms, winter storms,” Rasch said. “There certainly will be travel difficulties on I-80 but it probably won’t shut it down.”

In any event, the storms would be long overdue.

Sacramento hasn’t seen any rain since Nov. 18, and the region is well below normal for the “water year” that began Oct. 1. Only 0.87 inches of rain fell in Sacramento last month, about one-third of normal.

The U.S. Drought Monitor, a weekly index compiled by multiple federal agencies, says 95% of California is experiencing drought-like conditions. About a fifth of the state, including most of the Sacramento Valley, is in “extreme drought,” the monitor said.

Jan Null, a private forecaster with Golden Gate Weather Services, said a drought generally is defined as back-to-back dry years, “and right now we’re on track for that.” Although a dry December can often give way to weeks of heavy precipitation, this season is off to an unpromising beginning.

“We are starting off with a deficit,” Null said.

Last winter brought precipitation that was 38% below normal in the Sacramento Valley, according to the state Department of Water Resources.

So far this season, the Valley’s precipitation is 73% below normal.

Dry winters leave trees and other vegetation dried out and ready to burn — and last winter’s relatively parched weather was a factor in California losing 4 million acres to wildfire this year, a modern record.

In addition, the amount of rain and snow that falls in the Sacramento Valley is a critical piece of California’s overall water supply for the coming year: The Valley’s major rivers make up a major proportion of the water coursing through the Sacramento-San Joaquin Delta., the hub of the state’s north-to-south water-delivery system.

As a sign of how dry the weather’s been, on Dec. 1 the Department of Water Resources announced a mere 10% initial allocation to the local agencies that rely on the State Water Project. Those agencies include the Metropolitan Water District of Southern California, with nearly 20 million customers.

That allocation could grow over the next few months, but officials warned it could be a tough winter. “While we still have several months ahead of us, dry conditions persist,” said Water Resources director Karla Nemeth in a prepared statement.

This story was originally published December 11, 2020 at 10:12 AM with the headline "Rain, snow coming this weekend as Northern California wrestles with drought-like weather."