Flood Warning In Effect

The National Weather Service has issued an urban and small stream flood advisory for Marin, Sonoma and Napa counties today, as stormy weather has prompted local authorities to urge residents to use caution on the roads.

Flash flood warnings have been in effect in several parts of the Bay Aream including Willow Brook Creek in Penngrove, near Petaluma, National Weather Service officials said.

There have been no reports of power outages or major damage in the Twin Cities area, but crews are in the field looking for downed branches and backed up sewer drains.

Flash flood warnings mean that flooding is either occurring or is imminent. Authorities advise residents to avoid crossing swiftly flowing water of unknown depth, to move to higher ground if flooding is observed, and to report flooding to the nearest law enforcement agency.

Streams and creeks may rise but property damage should be minimal, National Weather Service officials said.

"The heaviest rain is in Marin, Napa and Sonoma counties with up to a quarter-inch per hour," National Weather Service forecaster Steve Anderson said.

Anderson said there have been reports of small hail and lightning in the Point Reyes National Seashore. The weather service has also issued a high-surf advisory for areas along the coast including the Point Reyes National Seashore, the San
Francisco Peninsula coast, northern and southern Monterey Bay and Big Sur
coast.

The advisory is in effect until 3 p.m. due to dangerous conditions related to tidal cycles, high winds onshore, and swells of up to 15 feet, according to the weather service.

"It's slowly moving south," Anderson said of the storm system. "The greater Bay Area will start to see some of that heavy rain by midday."