The Bay Area is prepared for a quadruple threat: rain, wind, surf and tides

A flood warning is in effect for the North Bay from Friday to Saturday afternoon from 2 p.m. Three waterways in Sonoma County are at risk of flooding: Laguna de Santa Rosa, the Russian River and Mark West Creek.

“If there is a thunderstorm or really heavy showers, there is a risk of flooding,” Sarment said.

King tides — caused by a stronger-than-normal gravitational pull when the sun, moon and Earth align — could push water up the coast and bay shores through Monday, with tides ranging from 5 to 12 feet at high tide. In addition to the higher tides, the weather service has issued a high surf advisory with large breaking waves in the 18 to 22 foot range from 1 p.m. Thursday through 4 p.m. Saturday.

“Because the tide will be higher overall, these larger waves may travel further up the beach,” Sarment said. “Overall, it won’t be a good weekend for going out.”

The higher tides increase the risk of flooding in places like the Embarcadero in San Francisco and the Mill Valley-Sausalito bike path in Marin County. Saturday’s highest tides could reach nearly 12 feet north of the coastal community of Alviso, San Jose, according to the California King Tides Project.

The California Coastal Commission is asking the public to submit photos of waves and rising groundwater during this weekend’s king tide. The images will be used by climate scientists and government officials “to validate sea level rise models and assess local vulnerabilities to erosion and flooding,” the commission wrote in a news release.

Conditions will improve Sunday before a third round of rain moves across the Bay Area on Monday, but Sarment said the system’s impact next week looks minor so far.

There’s good news for the not-too-distant future: After next week’s storm, the region will have “better weather” in time for the Christmas holiday, she said.