Dangerous waves expected this holiday weekend

Authorities are warning tens of thousands of beachgoers to exercise caution Sunday as forecasters predict a parade of powerful waves that will pound south-facing shorelines throughout the July 4 weekend.

The swells, formed by a strong storm near New Zealand, will generate waves with faces of up to 8 feet along beaches in San Diego, Orange, Los Angeles and Ventura counties, according to forecasters at Surfline.com. Large surf is expected to continue through Tuesday.

As much as the forecast delights surfers, it has prompted public warnings from surf experts and lifesaving officials, especially for those not familiar with the rhythm and power of big surf.

When the swell arrives Sunday morning, the initial waves will be followed by long lulls of few to no waves. Then, a series of large waves will sweep over previously dry areas, according to surf forecasters. The situation can pose a danger to unsuspecting people who may be walking on steep beaches, exploring tide pools, standing in rocky areas or fishing from jetties or breakwaters.

“Everyone should take seriously this surf forecast,” said Ken Kramer, a district superintendent with the state Department of Parks and Recreation who overseas state park beaches from San Clemente to Huntington Beach. “It’s going to be dangerous.”

The busy Fourth of July weekend, along with Memorial Day and Labor Day weekends, often tax the resources of local and state lifeguards. This weekend promises to be doubly difficult, they said, as crowds arrive at the same time as one of the biggest swells of the summer.

Weather forecasters are predicting morning clouds that will give way to sunny afternoons Sunday and Monday — conditions that will attract the beachgoing masses just as the tide is at its highest point and waves are rushing high onto beaches, soaking towels and demolishing sand castles.

Southern California logs an average of 130 million “beach visits,” a year, according to a study of attendance records at 75 beaches. A visit is defined as an individual making a trip to the beach on a particular day. Most of those visitors congregate on broad, popular stretches of sand, such as Zuma Beach in Malibu, Santa Monica State Beach and Huntington Beach in Orange County.

In summer months, more than half of those visitors — 54% — go into the water to wade, swim or surf.

Lifeguards said they will be ready for the human tide meeting the long weekend’s larger-than-usual waves. All towers will post guards, and patrols will be out in full force in beach vehicles and rescue boats. Conditions like those forecast for this weekend often result in drownings, particularly when waves knock fully clothed people off rocks or walls. Problems also occur when up-rushing whitewater surprises small children or people dozing on the beach.

Kramer cautioned parents to keep a close watch on children playing in the surf who could be vulnerable to waves rushing up the beach. “We recommend for folks who are not experts in the water that they celebrate America’s birth firmly on the beach or farther up on the sand.”

“Drowning is a preventable accident,” Kramer said. “Our goal is no drownings.”

The United States Lifeguard Assn. offers 10 tips to avoid trouble in the ocean. They include swimming near a lifeguard, never swimming alone and always swimming sober.

The big swell is likely to increase rip currents, which are rivers of wave-driven water headed back to sea. Lifeguards recommend that anyone caught in such a current resist panic and not try to fight the current. Instead, swimmers should relax and begin swimming parallel to shore, heading back to land only when they are free of the current.

Visitors have less room on most beaches than they did decades ago, as many of Southern California signature sandy beaches have been shrinking. The strips of sand are caught between rising sea levels and coastal armoring — usually concrete walls or rock embankments built to protect roads, houses and other structures.

Sea levels off California have risen about eight inches on average over the last century. Depending on the slope of the beach, each inch of sea-level rise claims about 50 inches of land. Beaches, which would migrate inland if unencumbered, are blocked by human-engineered fortification.

This week’s Southern Hemisphere swell will not hit all beaches equally. The south-facing beaches in San Diego and Orange counties will see the largest surf. Some of the beaches in Santa Monica Bay will be sheltered from the biggest waves by San Clemente and Catalina islands and the Palos Verdes Peninsula, until the swell direction begins to swing more westward Monday and Tuesday.

The swell is expected to create another spectacle at the Wedge, a famous surf spot next to the mouth of Newport Harbor. Body surfers will test their nerves and their necks on waves that can double in size after refracting off the rocks and then slamming onto the shallows or directly onto the sand. Forecasters project that some sets at the Wedge could reach 15 feet.

ken.weiss@latimes.com