A powerful south swell rolled into Southern California on Tuesday, bringing some of the biggest summer surf the region has seen in years and prompting urgent warnings from lifeguards and weather officials.

The National Weather Service issued a Beach Hazard Statement through Thursday afternoon, with the largest waves expected Tuesday and Wednesday.

Orange County is taking the brunt of the swells, with surf forecast between 8 and 10 feet in some areas and up to 15 feet in others.

Early Tuesday, waves overtopped rock jetties at Newport Beach and Dana Point, while rough surf pushed beneath piers in Huntington Beach and San Clemente.

At Newport Beach’s famed Wedge, waves could reach the 20-foot range as incoming swells combine with reflected waves from a jetty, creating the break’s signature towering surf.

Officials warned of dangerous ocean conditions across the coast.

“There is an increased risk of ocean drowning. Rip currents can pull swimmers and surfers out to sea. Waves can wash people off beaches and rocks, and capsize small boats nearshore,” NWS officials warn.

In San Diego County, surf was expected to reach 4 to 7 feet with waves up to 8 feet, some were that big but most were in the 6-foot range.

Los Angeles County’s south-facing beaches were forecast to see waves of 3 to 6 feet with larger sets exceeding 7 feet.

The swell has also raised concerns about coastal flooding.

In Laguna Beach, the west parking lot at Aliso Beach was closed because of flooding and large surf.

In Newport Beach, crews built sand berms to help protect beachfront homes from incoming water as high tides are expected to peak at 5.3 feet Wednesday evening and 5.8 feet Thursday evening.

Newport Beach lifeguards increased staffing, placing personnel at all towers and deploying patrol units and rescue vessels.

“Beachgoers are urged to use caution,” a Newport Beach warning reads.

“Always swim near an open lifeguard tower, check with a lifeguard before entering the water and pay attention to tower flags indicating current ocean and conditions.”

The National Weather Service said the swell should gradually ease Thursday but remain sizable through the weekend.

“Remain out of the water to avoid hazardous swimming conditions,” NWS officials said.

Officials advise anyone caught in a rip current to call for help, remain calm and float to conserve energy.

If possible, swim parallel to shore rather than directly against the current.

For families seeking calmer waters, officials recommend areas north of Newport Pier, Seal Beach, Baby Beach in Dana Point Harbor and the lagoon beach at Newport Dunes.