A so-called bomb cyclone could deliver the biggest storm in 60 years to Northern California and the San Francisco Bay Area this week, weather officials warned Nov. 18.
It’s been 60 years since the region experienced this type of storm, according to National Weather Service meteorologist Rick Canepa, based in the San Francisco area.
The storm would be the first atmospheric river system of the season, weather officials reported, and could dump up to 11 inches of rain in some areas, including northwestern Sonoma County.
“It’s a really early start to winter,” Canepa told The Epoch Times.
The powerful bomb cyclone, a system of low pressure that quickly gains strength, could slam parts of Northern California starting Tuesday.
Cold air from the northwest is expected to meet up with southwest water vapor from Hawaii, creating classic atmospheric river conditions that bring drenching rain and possibly coastal flooding.
“These produce a lot of precipitation and that’s exactly what the models are forecasting,” Canepa said. “The highest amounts of rain will be from the Golden Gate northward.”
Three to seven inches of rain are expected in most of the San Francisco region through Friday, according to the weather service.
“That would be much above normal,” Canepa said.
“Sharp rises of rivers, creeks, and streams are expected, along with ponding of water in low-lying areas,” the weather service posted.
Frost and freeze warnings were issued by the weather service Monday and Tuesday for the valleys north of the San Francisco Bay area. Freezing temperatures were expected both nights.
A flood watch was also issued for the region starting Tuesday through Thursday night, Canepa said.
The strongest winds were expected to hit southwest Santa Barbara County, Ventura County mountains, and northwest Los Angeles County.
Gale-forces winds reaching up to 35 knots, or 40 mph, were also forecast to arrive Monday night for the outer waters, causing dangerous sea conditions which could damage small or large vessels, according to the National Weather Service.
The gusty northerly winds could last seven days and cause hazardous driving conditions, especially for trucks and other high-profile vehicles. The weather service also warned of possible downed trees and power lines.
A high-surf advisory was also issued for San Luis Obispo County and Santa Barbara County beaches Monday night, which ends about 9 a.m. Tuesday, the weather service reported. The high surf could create large breaking waves reaching up to 11 feet across the west- and northwest-facing beaches with dangerous rip currents.
The rainfall was expected to hit the southern region later in the week, possibly starting Friday, according to the National Weather Service in Los Angeles.
The weather service expects about one inch of rain to fall across the region during the weekend. If the atmospheric pressure weakens, Southern California could get much more rain, according to the forecast.