An “atmospheric river” storm soaked much of the Bay Area on Tuesday, triggering widespread roadway flooding and mudslides. Monday night’s storm, complete with wind and rain, had crews working into the early morning. The Lake County Sheriff’s Office issued the closure of several roadways.
Hannah Chandler, a meteorologist at the National Weather Service base in Sacramento, said Monday night’s storm marks the brunt of February’s precipitation. Between Monday afternoon and yesterday afternoon, 2 inches fell on Mount Konocti. Chandler estimated another 1-3 inches before Saturday.
“It should be clearing out by Saturday and Sunday,” she said.
She also said the single storm alone proved enough to exceed the average February precipitation of around 0.2 inches, according to averages taken since 1954. In more recent years, Lake County has experienced an average of around 7 inches in January and 6 inches in February, except for the recent drought years. In January, Lake County took on 11.3 inches of rain, according to the Sacramento NWS.
As of now, the Lake County Public Services District doesn’t have a clear estimate regarding damages caused by the storm. Road servicing and potential repairs will be calculated within the next couple days as rains clear up.
Meanwhile, Clear Lake continues to press toward flood stage, hitting 8.64 on the Rumsey Gauge as of 4:15 p.m. on Tuesday, well over the normal full mark of 7:56.
Many of the low-lying roads that closed in January’s unrelenting rains have already flooded once more, and many more roads have been temporarily closed due to road slip outs, downed trees and mudslides.
Those mudslides temporarily closed Twin Valley Road in Clearlake Oaks, Anderson Springs Road and Rose Anderson Road in Cobb.
Likewise, trees fell on sections of Deiner Drive and Salamina Drive on Cobb Mountain.
The previous slip out, which affected Socrates Mine Road in late January, continued to deteriorate the road, but traffic can still pass using the unaffected lane.
Water levels overtook several more roads, warranting the closures of Argonaut Road, Bell Hill Road and Clark Drive in Kelseyville. Lakeport also took on flooding in the usual places, including Scotts Valley Road and South Main Street. Hill Road near Sutter Lakeside Hospital was closed due to a mudslide.
Nice’s stretch of Lakeshore Boulevard closed from Hammond Avenue to Stokes Avenue, and other areas of Upper Lake experienced flooding and washouts on Elk Mountain Road, Scotts Valley Road and Bartlett Springs Road. Waters completely washed out Elk Mountain Road near mile marker 29.6, and the sheriff’s office has no estimate of when that road will reopen.
The sheriff’s office also recommends four-wheel drive in swamped, flooded, or otherwise eroded sections of roadways.
The Hidden Valley Lake Community Service District reported rising waters in their vulnerable neighborhood; sheriff’s office deputies responded to the report but saw no need to evacuate residents at this time. However, they encouraged locals to prepare for such an evacuation, should water levels increase further.
Pacific Gas & Electric reported outages occurring in mostly urban areas such as San Francisco, Oakland, Napa and Santa Rosa. Shielded by the coast’s mountainous terrain, Sacramento experienced far fewer outages, most of which affected only a small number of customers.
Willits suffered an outage that left around 300 customers without power. As of yesterday, PG&E has issued crews to sort out the damages and restore power.
Despite the massive amount of outages, Lake County saw only three outages in Clearlake, Middletown and Kelseyville, each reportedly affecting fewer than ten customers.
Reports of damage flooded in from the Bay Area and Northern California, including a major slide in the Santa Cruz Mountains which caused the closure of all lanes of Highway 17.
A major mudslide on northbound Highway 17 at Vine Hill Road was reported just after 10 a.m., and by 1:30 p.m. Officer Trista Drake of the California Highway Patrol said that all four lanes of the highway in both directions will likely be closed at least until Wednesday.
“This is probably the largest slide that we’ve seen this year,” Drake said. “It’s definitely larger than the one a few weeks ago. It’s pretty amazing.”
Tons of rock, mud and broken trees crashed into the northbound lanes, flipping a pickup truck over the center divider. By mid-afternoon, rocks and mud were still coming down, flowing into the southbound lanes as CalTrans crews worked to remove the debris and begin to stabilize the hillside — the same location of another mudslide that close the road last month.
Highway 152 from Gilroy to Watsonville remained closed due to earlier mud and rock slides, leaving motorists trying to head to and from the coast to the Bay Area a lengthy detour over either Highway 92 into Half Moon Bay, Highway 129 from the Hollister area into Watsonville or Highway 156 through Castroville in Monterey County.
The closure of the main connector between Santa Cruz and Silicon Valley was just one of dozens of issues on Bay Area roadways Tuesday as the storm delivered as much as 6 inches of rain in 24 hours to some locations.
Other roadway closures include a downed tree on Highway 35 and a slide on Highway 84 causing havoc in the area, according to the California Highway Patrol, who warned motorists to avoid the area.
Just before noon the Fremont Police Department reported the closure of Niles Canyon Road because of about 2 feet of standing water on the roadway.
As of 2 p.m., several locations in the North Bay and Santa Cruz Mountains had received more than 5 inches of rain in the past 24 hours, according to the National Weather Service. In the East Bay, Tilden Park in Oakland received 3 inches and Mount Diablo recived nearly 4 inches. Rainfall totals around the Bay Area in the past 24 hours include 1.2 inches at San Francisco and Oakland, .71 in Palo Alto, 2.12 in Mill Valley and 2.87 in Santa Rosa.
The heaviest rain passed through the Bay Area by mid-morning, and lingering showers are expected the remainder of the the day, according to Steve Anderson, a forecaster with the National Weather Service.
The National Weather Service also issued a flood warning for the Napa River near St. Helena and the San Lorenzo River in Felton, which was about 3 feet above flood level at 10 a.m.
In the Santa Cruz Mountains, Arnie Huddin of Capitola was driving north on Highway 17 when the hillside collapsed just north of Vine Hill Road. He said he was on his way to vacation in Lake Tahoe. The slide picked up and flipped his truck into the oncoming lanes, he said.
“I feel very lucky,” said Huddin, who was not injured. “And I was worried about driving in the snow.”
Raffi Nalvarian of San Jose was heading south at 9:45 a.m. on Highway 17 just before the hillside collapsed on the northbound lanes near Vine Hill Road. He saw a large Ford truck upside down and the driver getting out of the vehicle.
“That truck was covered in mud,” Nalvarian said. “The mud was probably 30 feet high. His truck got pushed from the northbound lanes to the southbound lanes. It was insane.” Nalvarian said the mud was high enough to hide vehicles.
Throughout the day, CHP officers were turning cars around on Highway 17 southbound at Bear Creek Road, at Redwood Estates and Summit Road. CHP officials said an update is expected later this afternoon, but that thousands of commuters should plan for alternative routes home.
“People should give them selves lots of extra time,” said Drake. “It’s inconvenient, but CalTrans is working at hard as they can.”
Atmospheric rivers are flowing columns of condensed water vapor. Strong ones can carry an amount of water vapor equivalent to 7.5-15 times the average flow at the mouth of the Mississippi River, according to the National Oceanic and Atmospheric Administration.
Damage caused by atmospheric rivers in December and January spurred Gov. Jerry Brown to issue emergency declarations. Mejia said this atmospheric river won’t be as strong.
The second system is expected to arrive Thursday. The “classic cold front” from the Gulf of Alaska will move quickly through the Bay Area, Mejia said. A quarter-inch to half-inch of rain is expected to fall in most urban locations and 1 to 3 inches in higher elevations.
Things will start to dry out Saturday, when a ridge of high pressure begins to build over the Bay Area, according to the weather service. Sunny skies with temperatures in the low 60s are projected for the weekend.
In the latest sign that the drought is over in Northern California, the Sierra Nevada snowpack on Tuesday hit 182 percent of the historic average, a stunning 124 percent of the April 1 average already. With 25 feet of snow having fallen in January, the Sierra Nevada now has more snow than at any time since 1995.
The rain so far this winter has arrived in the type of pattern that was all that water experts could have hoped for. It rained heavily in October, saturating the ground, and after a respite in November, there have been relentless, steady, soaking storms that have filled reservoirs across Northern California, with pauses of sunny days in between that has reduced flood risk.
“Up until now, we haven’t had any serious flooding issues,” said Marty Grimes, a spokesman for the Santa Clara Valley Water District. “The week in between storm systems helps avoid floods. The piling on of snow week after week is terrific. We’re well above the April 1 average now. It’s all fantastic. The only thing that could go wrong now is if the rest of February, March and April are exceedingly hot and dry, and it melts the snow.”
Rainfall totals throughout the Bay Area are all running above average for the season, which began on Oct. 1. Through Monday, including Santa Rosa, which has received an eye-popping 40.70 inches (185 percent of normal). Others include San Francisco at 19.51 inches (136 percent), Oakland at 16.83 inches (140 percent) and San Jose at 10.72 inches (121 percent).
Michael Todd of the Santa Cruz Sentinel and Paul Rogers and Harry Harris of the Bay Area News Group contributed to this report.
