The waves, double the size of most large summer swells, were the tallest recorded in several decades.
Massive waves have slammed into Hawaii’s south shores, blasting into homes and businesses, spilling across highways and sending tables and chairs crashing towards guests attending a wedding.
The waves, some more than six metres high (20 feet), are thought to have been caused by a combination of a strong south swell that peaked on Saturday evening, particularly high tides and rising sea levels associated with climate change, the National Weather Service said on Monday.
Chris Brenchley, the meteorologist in charge at the National Weather Service office in Honolulu, said they were the largest recorded in several decades. Most large summer swells that come from the south are no bigger than about 3 metres (10 feet), which would trigger a high surf advisory.
“We had some waves that were reaching 20 feet, 20 feet-plus even,” Brenchley said. “That’s getting on the level of historic.”
While singular events like this are hard to pin directly to climate change, Brenchley said the warming planet is playing a role.
“The most direct type of impact that we can use with climate change is the sea level rise. Any time you add just even small amounts of water, you raise that sea level just a little bit,” he said. “And now those impacts will be exacerbated whenever we have a large storm event or a … high, high tide.”
A wedding in Kailua-Kona was interrupted on Saturday evening when the large waves barrelled ashore, about five minutes before the ceremony was scheduled to begin.
Sara Ackerman, an author who grew up in Hawaii and attended the wedding, was filming when the waves crashed in. “It just was huge,” she said. ”It just came over the wall and just completely annihilated all the tables and chairs.”
The ceremony went ahead, with the newlyweds exchanging vows after the mess was cleared, she said.
Hawaii’s north shores, where professional surfers often compete, usually get much larger waves than other parts of the islands. The predominant swell hits the north shores in the winter and the south shores in the summer.
Lifeguards and rescue crews across the state conducted at least 1,960 rescues on the island of Oahu alone on Saturday and Sunday. Honolulu officials reported one serious injury when a surfer suffered a laceration to the back of his head.