The National Weather Service has issued a Red Flag Warning for the North Bay and East Bay as well as the Santa Cruz Mountains this weekend as a combination of gusty offshore winds and low humidity affect large parts of the San Francisco Bay Area.
The warning is in effect Saturday and Sunday, particularly for high-elevation areas of the North Bay, East Bay and Santa Cruz Mountains, where wind gusts could hit 70 mph, the weather service said Friday.
Maps of the warning area were posted on the weather service website.
The City of Berkeley warned residents of the Berkeley Hills to be prepared to evacuate. The city said the greatest risk in Berkeley would be overnight Saturday into Sunday morning.
The city urged residents to use extreme caution when operating BBQs, power equipment or other heat sources, such as idling cars. It reminded Alameda County residents to sign up for AC Alert, an emergency notification platform.
The city urged people to leave their phones on and to disable the "do not disturb" mode. Other tips shared with residents included putting a "go-bag" by the front door and planning multiple evacuation routes. Residents were asked to park off street, in order to leave roads clear for emergency vehicles.
Forecasters also issued a Wind Advisory this weekend for the North Bay interior mountains, Marin Coastal Range, East Bay hills, Santa Clara hills and Santa Cruz Mountains.
Meanwhile, minimum relative humidity was expected to dip from 25% to as low as 10%, with overnight recoveries of 25% to 45% for the North Bay, East Bay and the Santa Cruz Mountains on Saturday and Sunday, adding to the fire risk in these areas, forecasters said.
The weather service also issued a Frost Advisory for the North Bay valleys late Friday night into Saturday morning. Residents there are warned of potential damage to sensitive vegetation without adequate shelter. Moderate to major fire risk levels across much of the region will ease significantly beginning on Monday, forecasters said.