High Tides, Sneaker Waves and Up to 16-Foot Breakers Expected on the Bay Area Coast This Weekend

Anyone heading to the Bay Area shoreline this weekend should expect water higher than usual and surf that can turn dangerous with little warning.

The National Weather Service office for the San Francisco Bay Area has a Coastal Flood Advisory in effect from 9 a.m. Friday, Oct. 9, through 3 p.m. Tuesday, Oct. 13, for bayshore locations along San Francisco and Monterey bays. Forecasters say up to 1.2 feet of water above ground level is possible in low-lying spots near shorelines and tidal waterways.

When the tides peak

At the San Francisco tide gauge, the weather service expects high tide to run about 1.0 foot above normal at 11:22 a.m. Friday, then about 1.2 feet above normal near midday Saturday, Sunday and Monday: 11:50 a.m. Saturday, 12:18 p.m. Sunday and 12:46 p.m. Monday. Tuesday's 1:14 p.m. high tide is forecast at about 1.1 feet above normal. Those numbers include up to a foot of surge on top of the astronomical tide, and timing can shift up to 90 minutes earlier or later depending on location.

Expected impacts include flooding of parking lots, parks and roads, with only isolated road closures, plus water over coastal trails and cut-off access to some low beaches. The weather service advises not driving around barricades or through water of unknown depth.

Dangerous surf on the open coast

Separately, a Beach Hazards Statement runs from 7 a.m. Saturday through 2 p.m. Monday for the San Francisco Peninsula coast and the coastal North Bay, warning of breaking waves up to 16 feet, sneaker waves and strong rip currents, the San Francisco Chronicle reported. The weather service's surf forecast already calls for 8- to 12-foot surf on northwest-facing Sonoma and Marin beaches Friday.

Sneaker waves can surge well past the reach of earlier waves and knock people off rocks, while rip currents can pull swimmers away from shore quickly. Forecasters urge people to stay out of the water, stay off jetties, piers and rocks, and never turn their back on the ocean.

The Chronicle noted the local hazards don't depend on Hurricane Rachel, which is expected to weaken as it moves toward Southern California. Stronger northwest winds and already elevated water levels are the bigger concerns here, which matters for the Fleet Week crowds expected along San Francisco's northern waterfront.