Renewed flood threat, heavy snow: What to know about California’s next big winter storm
Another atmospheric river storm will bring flood risk to the Sacramento Valley for a third consecutive weekend, stirring up strong gusts while dumping several more feet of snow in the Sierra Nevada mountains.
The precipitation is expected in two rounds, National Weather Service forecasts show.
Rain should start in the Sacramento area around 10 a.m. Friday, with a break overnight before a heavier downpour begins Saturday morning. More than an inch could fall each day, forecasts show, while the foothills could get between 3 to 5 inches by the end of the weekend.
The weather service has a flood watch in place from 10 a.m. Saturday through 7 a.m. Sunday for a wide swath of Northern California, including the Sacramento Valley.
The capital region could see gusts Saturday approaching 40 mph, according to the weather service, with a chance of thunderstorms. A powerful thunderstorm early Tuesday morning brought gusts topping 50 mph, uprooting trees and disrupting morning traffic.
California has been pounded by a series of strong atmospheric river storms for more than two weeks, with state and local officials through Thursday reporting at least 19 deaths linked to the extreme weather.
“These storms are amongst the most deadly natural disasters in the modern history of our state,” Nancy Ward, director of California Governor’s Office of Emergency Services, said during a news conference midday Friday.
President Joe Biden on Monday approved an emergency declaration for California’s storms and flooding. Federal Emergency Management Agency Administrator Deanne Criswell said she spoke with Biden on Wednesday regarding storm damage, and would do so again after Friday’s news conference.
“He’s very focused on making sure that there are no barriers and that we don’t let bureaucracy get in the way,” Criswell said.
Major flooding in south Sacramento County during a New Year’s Eve storm killed at least three people. Two others in the county, a homeless man and woman, died in last weekend’s storm after trees fell on their tents in separate incidents, officials said.
County emergency officials issued a mandatory evacuation order last Sunday for Wilton and surrounding areas, which was lifted Tuesday morning as the Cosumnes River at Michigan Bar held below forecast expectations.
California ‘not out of the woods’ as flood risk persists
The Cosumnes River is forecast to rise to just below flood stage Sunday morning before receding, said Jeremy Arrich, manager of the state Department of Water Resource’s flood management division, during a virtual news conference Friday afternoon.
Recent flood control measures instituted along the Cosumnes River “have held well through the storms that we had earlier this week,” Arrich said.
Sacramento County officials this week have taken the rare step of opening Cal Expo as an emergency weather respite shelter for the homeless.
Northern California saw some respite with a dry Thursday, but other regions have seen dire flooding situations develop. The Salinas River in Monterey County overflowed, with authorities warning that by the weekend, the Monterey Peninsula could be cut off by floodwaters, essentially becoming an island for several days.
“Let me emphasize we are not out of the woods yet,” Ward said. “The threat to communities remains and waters will continue to rise even after the storms have passed. The impacts of these storms have been significant.”
Statewide, Arrich said the main areas of focus for flood risk are the Pajaro and Salinas rivers, in Santa Cruz and Monterey counties; the Cosumnes River in Sacramento County; Merced County’s Bear Creek; and the Russian River, in Mendocino and Sonoma counties.
The strong atmospheric river storms since late last month have improved California’s drought conditions substantially in the short term, according to state water officials and the U.S. Drought Monitor.
Molly White, the department’s state water operations chief, said California’s major reservoirs are now at 87% of their average level for this time of year, up from 81% at the start of the week.
“We’re certainly, across the state, seeing an increase in storage with this storm activity,” White said.
California’s second-largest reservoir, Lake Oroville, has increased by more than 100 feet since Dec. 1, White said, surpassing levels from 2021 and 2022.
Up to 6 feet of snow possible in the mountains
Yet another round of very heavy snow is en route to the Sierra Nevada range this weekend, with the weather service expecting anywhere from 3 to 6 feet at various locations.
Snow will drop from elevations of about 5,000 feet Friday to as low as 3,500 feet Saturday night, with mountain gusts up to 50 mph possible, according to the weather service.
A winter storm warning is in place across the mountains from 1 p.m. Friday through 10 p.m. Monday. Mountain travel is highly discouraged, with highway closures due to whiteout conditions likely.
The past half-dozen atmospheric rivers that have rolled through the state since late December have already pushed Sierra snowpack levels well above double their historic average for this time of year, according to the California Department of Water Resources.
The UC Berkeley Central Sierra Snow Lab, located at Donner Pass, said it recorded just over 6 feet of snow for the week ending Tuesday, followed by another 4 inches on Wednesday.
Most Sacramento power outages resolved
Nearly 350,000 homes and businesses served by Sacramento Municipal Power District lost power in last weekend’s extreme wind storm, which saw gusts exceed 70 mph at one point early Sunday.
SMUD as of Friday morning reported 750 customers still without power, a total that has been gradually whittled as the utility company recovers from what it has called the most damaging series of storms in its history.
More rain coming after next storm. When will it be dry?
Northern California’s wet weather won’t end with this weekend’s storm.
Yet another storm system will intensify Sunday night through Monday morning, according to weather service forecasts.
Moderate to heavy rain should finally clear out of the Sacramento region by around the middle of next week. Medium-range forecasts show much of California is expected to be drier than normal for the week of Jan. 19 to Jan. 25.
This story was originally published January 13, 2023 at 8:33 AM.
