A mildly rainy weekend was expected to give way to a full-blown storm Monday, with heavy showers, strong winds, high surf, thunderstorms and potential flooding throughout the Bay Area, weather experts said.
National Weather Service meteorologists spent much of Sunday warning residents not to grow too comfortable — gustier winds, they said, were forecast to culminate in an overnight downpour that would endure through much of the Presidents’ Day holiday.
Conditions deteriorated through Sunday evening, with alerts of wind speeds up to 50 mph issued in Santa Cruz and flash-flood warnings extended to areas of Monterey County, mainly around the Carmel River region that burned in the 2020 River Fire.
Later in the day, flood advisories were issued in Marin, Napa and Sonoma counties, though other parts of the Bay Area, such as Alameda and Santa Clara counties, remained safe from major flood concerns by press time.
“This isn’t going to be as aggressive as we saw two weeks ago, but there will be some issues this evening to tomorrow” with moderate to heavy rains across the area, said Brayden Murdock, an NWS meteorologist, in an interview.
“It’s not the worst so far this season, but we still have concerns,” Murdock added. “Some things could be very impactful.” He said the forecast through Wednesday is for 1½ to 2½ inches of rain across the region; higher peaks could receive 3 to 5 inches.
Heavy rain was expected all night, while another low-pressure system on Monday’s forecast raised concerns among weather officials, who advised residents to stay alert.
“Be sure to have multiple ways to get warnings tonight!” the NWS Bay Area wrote in a social media post.
A flood watch that began Sunday morning was expected to remain in effect through 10 a.m. Wednesday. A small craft advisory, which started at 9 a.m. Sunday, will last until 3 a.m. Tuesday.
In the greater Lake Tahoe area, a warning of a storm that could impact travel remains in effect from 4 p.m. Sunday to 10 a.m. Wednesday.
UC Berkeley’s Central Sierra Snow Lab, at Donner Pass, recorded 7½ inches of snow at 8 a.m. on Sunday. But more snow is coming. The lab said they expect 18 to 30 inches of snow through Wednesday afternoon.
Winds were still just beginning to pick up by mid-afternoon Sunday, but the storm warnings led organizers to cancel a planned yacht-and-aircraft event at Treasure Island to commemorate the 85th anniversary of the Golden Gate International Exposition.
“Yes, we know it’s gorgeous outside right now, but don’t let that blue sky fool you!” the NWS Bay Area wrote in a social media post earlier in the day. “Rain is on the way! Expect clouds and showers to increase in the afternoon.”
The NWS in Reno said a period of heavy snow, that could reach 2 to 4 feet above 7,000 feet, was expected to arrive Sunday evening and continue through Monday morning and then periods of moderate to heavy snow will follow Monday afternoon through early Wednesday.