Forecasters warn king tides, south swell could trigger coastal flooding

Forecasters warn king tides, south swell could trigger coastal flooding
(Image: Hawaii News Now)

WAIKIKI (HawaiiNewsNow) - Besides hazardous surf from Hurricane Hector, forecasters are tracking king tides and an incoming south swell.

All that will mean elevated water levels — and the potential for coastal flooding.

The wave energy from Hector will mainly impact the southern and eastern shores of the Big Island and parts of Maui, forecasters said.

"The energy, the swell that comes out from a hurricane, is usually contained with a pretty narrow ray of energy so once the hurricane goes by, things are going to settle down fairly quickly," said Robert Ballard, National Weather Service science and operations officer.

Due to the highest tides of the year combining with a south swell, water levels will be higher than usual from Thursday through the weekend.

Authorities are warning people to be cautious on Thursday and Friday afternoon in low-lying areas, such as Waikiki.

"People should be careful with regard to walking on the beaches when these waves are breaking. We probably will see erosion of a number of beaches. It should be temporary erosion," said Chip Fletcher, an associate dean at the University of Hawaii at Manoa's School of Ocean and Earth Science and Technology.

But experts aren't expecting any new water level records to be set.

"We might see beach inundation where an occasional wave will wash over the entire width of the beach and create a wet beach. This is not a damaging storm-type event," said Dolan Eversole, a coastal processes specialist for the University of Hawaii Sea Grant College Program.

"Even with this increased high surf, we're not expecting the water levels to be anything higher than what we saw last summer. In fact, even with the hurricane swells, we're looking at it probably being something less than what we saw last summer."

The UH Sea Grant College Program is asking people to take pictures of coastal areas they're familiar with on Thursday and Friday for the Hawaii and Pacific Islands King Tides Project.

"The photographs and the observations that people send in really help us to understand King Tides, but also what future sea level rise might look like along our coastlines," said Maya Walton, program leader for the U.H. Sea Grant College Program.

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