A few days of heavy rain have prompted the National Weather Service to issue a flash flood watch for the entire North Bay this afternoon, a forecaster said.
At the same time a portion of Great Highway in San Francisco is closed due to flooding early this morning, according to the city's Department of Public Works Twitter page.
Southbound lanes between Lincoln Way and Sloat Boulevard were shut down as of about 4:20 a.m., according to the department's tweet.
There is no estimated time of when the road will reopen.
The flood watch was in effect for Napa, Sonoma and Marin counties until today at 3 p.m., NWS forecaster Austin Cross said.
Parts of the North Bay have received several inches of rain in the last 48 hours, Cross said.
As of noon today, Woodacre in Marin has recorded over 10 inches, and Sebastopol in Sonoma County has received 8.5 inches, Cross said.
An urban creek and small stream flood advisory has also been issued for North Bay counties, Cross said.
Widespread flooding has not been reported, though isolated flooding has blocked some roads throughout the North Bay.
Motorists were advised to drive slowly and never drive through flooded roadways.
Rainfall was expected to taper off later today, Cross said.