Towering waves on Hawaii’s south coast crashed into homes and businesses, spilled onto highways and upended weddings over the weekend.
The big waves – some over 20 feet (6 meters) high – came from a combination of a strong southerly swell that peaked on Saturday night, especially high tides and rising sea levels associated with climate change, the National Weather Service said Monday.
A Saturday night wedding in Kailua-Kona was interrupted when a series of large waves swamped the event, sending tables and chairs crashing into guests.
Sara Ackerman, an author who grew up in Hawaii and attended the wedding, filmed the waves as they came ashore.
“It was just massive,” she said. “I was filming it, then it fell on the wall and completely wiped out all the tables and chairs.”
She said it happened about five minutes before the ceremony was scheduled to start.
“It wasn’t like a life-threatening situation by any means,” she said. “It was just like, ‘Oh my God…what are we going to do? Where are we going to set the tables?'”
She said they went ahead with the ceremony and cleaned up the mess after the newlyweds exchanged vows.
“We had the ceremony and it was beautiful, with all the (sea) spray,” she said. “The ocean was really wild. So it was great for photos.”
Chris Brenchley, the meteorologist in charge of the National Weather Service office in Honolulu, said several factors came together to create such huge waves.
“Waves over 12 or 15 feet (3.66 or 4.57 meters), those get extremely big and really rare to have,” he said. “It’s the biggest for several decades.”
Brenchley said the swell was produced in the South Pacific, where it is currently the winter season.
“They had a particularly strong winter storm where the winds were concentrated directly to places like Samoa and then further north to Hawaii,” he said.
Remnants of Hurricane Darby passed south of Hawaii but had no major impact on waves, he said.
While it’s hard to directly attribute singular events like this to climate change, Brenchley said global warming plays a role.
“The most direct type of impact we can use with climate change is sea level rise. Every time you add even small amounts of water, you’re raising sea levels a little” , did he declare. “And now those impacts will be exacerbated any time we have a big storm or a…high tide.”
Most big summer swells that come in from the south don’t exceed about 10 feet (3 meters), which would trigger a high surf warning.
“We had waves that were up to 20 feet (6 meters), 20 feet and even more,” Brenchley said. “It becomes historic.”
Hawaii’s northern shores, where pro surfers often compete, typically get much bigger waves than other parts of the islands. The predominant swell hits the northern shores in winter and the southern shores in summer.
Lifeguards and rescue teams across the state had a busy weekend.
They performed at least 1,960 rescues on the island of Oahu alone Saturday and Sunday.
Honolulu officials reported a serious injury when a surfer suffered a laceration to the back of the head.