Another windy deluge is expected to slam into the Bay Area early this week, potentially sending some streams over their banks while also raising the specter of widespread power outages from wind-battered trees falling onto power lines.
The latest atmospheric river-fed storm is expected to begin impacting the Bay Area late Sunday night — first dropping rain over the North Bay before moving south overnight toward the Peninsula, the East Bay and the South Bay early Monday morning, said Brayden Murdock, a National Weather Service meteorologist. He warned residents to prepare for the storm by signing up for emergency alerts, given the high likelihood of flooding and high winds in parts of the Bay Area.
“This is going to be dangerous,” Murdock said.
The storm marks the latest atmospheric river to drench Northern California over the last couple of weeks, whipsawing the region from one of its driest three-year runs in recorded history to a state of perpetual flood risk. Still, even though the recent wet weather has begun to alleviate drought conditions across Northern California, experts say even more moisture is needed to put an end the region’s historic drought.
The National Weather Service issued a flood watch through Tuesday for almost the entire Bay Area. Among the rivers most at risk of flooding are Alameda Creek near Niles Canyon and Sunol; Arroyo de la Laguna at Verona in Alameda County; Coyote Creek at Milpitas and at Edenvale; Pacheco Creek near Dunneville in the South Bay; and the San Lorenzo River in Santa Cruz County. To the north, the Russian River could flood near Guerneville.
The creeks most at risk of flooding in Santa Clara County include Uvas Creek along Highway 101 in Gilroy; San Francisquito Creek in Palo Alto; Ross Creek at Cherry Avenue in San Jose; Upper Penitencia Creek at Mabury and King roads in San Jose; Guadalupe River at West Alma Avenue in San Jose; Sunnyvale East Channel at Tasman Drive in Sunnyvale; and West Little Llagas Creek in Morgan Hill.
Updated forecast rainfall totals for round 2, expected to begin tonight between 10 pm and midnight. The heaviest rain will occur between 4 am and 4 pm Monday. Slight lowering of totals from the Bay Area northward and southern valleys. More details in follow up tweet.#CAwx
— NWS Bay Area 🌉 (@NWSBayArea) January 8, 2023
The first drops of rain are expected to begin falling over the North Bay around 9 p.m. Sunday, with the heaviest bands of rain hitting about an hour later, Murdock said. In San Francisco, Oakland and San Jose, the first rain will begin falling an hour or two before midnight, with the heaviest rain hitting a few hours before sunrise on Monday.
The heaviest downpours should begin to subside by about noon Monday, though chances for additional precipitation should linger through Tuesday.
Most of the Bay Area — including San Francisco and Oakland — could see 2 to 4 inches of rain by Tuesday, Murdock said. San Jose is expected to see closer to 2 inches from this storm.
The heaviest rainfall should fall over the waterlogged Santa Cruz Mountains, where 5 to 7 inches of rain is expected, with a few places seeing as much as 8 inches. To the south, the Santa Lucia Mountains along the Big Sur coast could see even more rain, with forecasts calling for that area to receive up to 10 inches of rain in some spots.
In addition, dangerously blustery weather could once again raise the risk of power outages from trees falling onto power lines.
Winds of 25 to 35 mph are expected across much of the Bay Area’s lower-lying regions, with gusts potentially hitting 60 mph, the National Weather Service said in issuing a high wind warning. Along the coast and the Bay Area’s peaks, forecasters are expecting winds of 35 to 50 mph and gusts of up to 80 mph.
“This is also going to be a wind event,” Murdock said. “Very strong winds — and when you do have strong winds after seeing plenty of moisture in the soil, you can see trees fall.”
High Wind Warning has been issued for our region starting tonight at 8 PM into Monday 4 PM. Expect southerly winds near 20 to 35 mph with gust up to 60 mph in the valley locations and 35 to 50 mph with gust up 80 mph along the coast and highest peaks. #CAwx #highwind pic.twitter.com/VbzaXV22ez
— NWS Bay Area 🌉 (@NWSBayArea) January 8, 2023
The storm comes after a weaker atmospheric river-fed storm moved through the area on Saturday — the final remnants of which dropped hail and packed 40 mph winds across parts of the North Bay and San Francisco late Saturday night and early Sunday morning.
About 8,500 Pacific Gas & Electric customers were without the Bay Area as of 11 a.m. Sunday morning due to the storms, most of them in the North Bay and the Peninsula, according to the utility provider.
Later this week, three additional storms fed by atmospheric rivers streaming across the Pacific Ocean are expected to hit Northern California. While none of them are expected to be as powerful as the storm hitting late Sunday night and Monday, they could still cause flood damage in parts of the Bay Area, said Michael Anderson, California state climatologist.
He said that federal resources have been mobilized to help the National Weather Service’s forecasts. Five Air Force C-130s and a National Oceanic and Atmospheric Administration aircraft are flying over the Pacific Ocean – reaching as far as Hawaii – to gather data on the coming storms.
“These next storms are really going to start seeing some flood stages be reached,” said Anderson, during a call with reporters Saturday. “There’s a lot to keep an eye on and a lot to track.”