Ocean Beach Could See 25-Foot Waves This Weekend as Massive Storm Approaches

Powerful storms brewing in the Gulf of Alaska are expected to bring heavy rain, strong winds, and some of the biggest waves in years to the Bay Area this weekend, with Ocean Beach potentially seeing waves topping 25 feet. Breaking waves of 30 to 40 feet are possible along exposed stretches of the Northern California coast from late Friday through Saturday afternoon, as the Chronicle reports . On Saturday morning, significant wave heights are forecast to reach 20 to 30 feet between San Francisco and Crescent City, which is about 350 miles north of SF, and individual waves could be considerably larger. West-facing beaches are expected to take the brunt of the swell, while some north- and south-facing beaches may be more sheltered. Waves this large can reportedly surge hundreds of feet up the beach, making even seemingly dry sand dangerous. Officials are urging people to stay out of the ocean and avoid beaches during the storms. As SFist reported Monday, the National Weather Service extended last weekend’s coastal flood advisory through Friday for low-lying coastal and bayshore areas from Sonoma County to Monterey County. High tides could cause up to 1.6 feet of flooding, along with road closures and coastal erosion. Residents should allow extra travel time and never drive through standing water. Residents and business owners can receive 10 sandbags each from SF Public Works to prevent flooding, with several “ Sandbag Saturdays ” events in various neighborhoods through December 5. Sandbags can also be picked up from Public Works year-round, Monday through Saturday. The elevated water levels are partly tied to El Niño-related ocean warming and powerful underwater Kelvin waves moving up the Pacific coast. Tides are running more than a foot above typical levels, allowing waves to break farther up the beach and carry more sand back out to sea. Even higher tides are expected around Thanksgiving and Christmas. According to the Chronicle, National Weather Service meteorologist Joe Merchant warned that this weekend’s waves could be “pretty problematic,” with seven or eight additional pulses of wave energy possible through Thanksgiving. High surf warnings are very likely this weekend, and rough seas could continue Sunday, followed by another large swell as early as Monday. The biggest waves may draw professional surfers to Half Moon Bay’s Maverick’s, where waves have reportedly reached 60 feet or more during similar storm patterns. However, strong winds and rain could make for choppy, unpredictable conditions. The Pacific swell itself will have limited reach inside San Francisco Bay, but strong southerly winds could reportedly create hazardous conditions for boaters and ferry passengers Friday. Winds of 20 to 30 mph, with gusts up to 45 mph, are possible that afternoon, pushing waves from south to north across the Bay. The storm’s cold front is also expected to bring heavy rain, particularly to the North Bay, coastal ranges, and areas around the Bay, including San Francisco and Oakland, as the Chronicle reported in a separate article. Downpours and thunderstorms are possible, while southwest wind gusts could exceed 40 mph in exposed areas near the Golden Gate and Carquinez Strait. Strong winds and heavy rain could bring down trees and limbs, potentially causing scattered power outages. Saturday should bring a break from the worst of the storm, though conditions are expected to remain unsettled. Another front could arrive late Saturday or early Sunday, bringing additional showers, although forecasts for Sunday remain uncertain and suggest less rain than Friday. Related: Bay Area Under Coastal Flood Advisory as Potential 16-Foot Waves Threaten Beaches