On Monday, first of three rainstorms brings Bay Area a “solid soaking,” minor flooding

President’s Day was greeted by thick gray clouds and rainfall across the Bay Area Monday as the first of three back-to-back rainstorms brought minor flooding to some parts of the region.

The storm, which arrived Sunday and brought its heaviest rainfall overnight into early Monday morning, dumped the most rain on the North Bay and coastal mountains, with about two to three inches falling in some areas, said National Weather Service meteorologist Matt Mehle. Rain was expected to continue through the day Monday before a second storm arrives Tuesday.

“The heaviest will be the first part of (Monday), and then we’ll kind of taper off the showers,” Mehle said. “But we’re not completely done yet. This storm door does remain open, and we’ve got another frontal passage that will bring additional rainfall Tuesday and Wednesday, and then we actually have a third system that’s going to round out the work week, Thursday to Friday with additional rain chances.”

“It’s going to be a wet week,” he added.

By Monday morning, San Jose and Oakland had seen about an inch of rainfall, Mehle said. Morgan Hill saw an inch and a quarter, while Concord had an inch and a half. Livermore saw just about 0.6 inches.

The region was expected to get another one-tenth to one-quarter inch throughout the rest of Monday, he added.

“We are seeing some variability when it comes to rainfall, but ‘solid soaking rain’ is a good way to describe it for most of the Bay Area,” Mehle said. “The radar is still pretty lit up. … There’s still a decent amount of rainfall moving through and that the heavy stuff that we’re seeing now will continue into the first part of this afternoon, but the second half of the day we’ll see much less rainfall.”

The storm was paired with cooler temperatures that are expected to cool even further as the week goes on, Mehle added.

The California Highway Patrol reported some minor roadway flooding in Redwood City that didn’t have much impact, Mehle said. Further flooding was reported in Monterey County. Chances of flooding remain active across the region until around noon.

“The creeks and streams are filling out. The culverts are kind of full and running pretty solid,” he said. “The way to describe this would be more minor or nuisance-style flooding.”

A coastal flood advisory is in place for the San Francisco Bay through Tuesday due to the potential of up to a foot of high tide flooding in low-lying areas, according to NWS.

Whether just going out and about or hitting the road for the holiday weekend, drivers should be careful of flooded roads and hydroplaning.

“If you encounter a flood of roadway, turn around, don’t try to drive through it,” Mehle said. “The other thing too is, I would be cautious with speed and how fast you’re driving.”

For the first time this season, Bay Area residents will likely be able to see snow dusting the Diablo and Santa Cruz mountains, Mehle added.

“People might not get it in the valley, but they’ll at least be able to see it off in the distance,” he said.

Storms are also bringing snowfall to the Sierra Nevadas, and anyone driving through the mountains for the holiday weekend should be sure to check Caltrans for road conditions, Mehle added.

Though the storm passing through the region Monday is expected to be the wettest of the three, the second storm will come close to having similar rainfall totals, Mehle said. The third storm is expected to drop the least precipitation on the region. Those storms will also bring colder air that will drop temperatures in some regions, including San Jose, to the high 30s and low 40s, as well as a low chance of thunderstorms across the Bay Area.

“The concern there is obviously for people that are unhoused or don’t have adequate shelter,” Mehle said. “Damp conditions from the recent rain, the ongoing rain and cold overnight lows will just make it feel that much worse.”