High surf advisory for west coast of Big Island goes into effect this morning

A high surf advisory will be in effect from 6 a.m. today through 6 p.m. Wednesday for the entire west coast of the Big Island, from ‘Upolu Point in North Kohala through South Point in Ka‘ū, as a series of large west-northwest swells moves in that will produce advisory level surf through at least Wednesday.

The National Weather Service in Honolulu forecasts large breaking waves of up to 10 feet for the western shorelines of the island.

“Strong breaking waves and strong currents will make swimming dangerous,” said a Hawai’i County Civil Defense message at just after 4 p.m. Monday. “Beachgoers, swimmers and surfers should heed all advice given by ocean safety officials and exercise caution when entering the water.”

Remember: When in doubt, don’t go out.

More information and other county notices related to the high surf advisory can be found online at the Hawaiʻi County Hazard Impact Map.

The first of the series of swells began building Monday night and should peak today. A buoy west of Kaua’i by just after 8:30 p.m. Monday was already indicating a 7 to 8 food northwest swell with a medium to long period.

Swell period is the time between crests or troughs of waves.

The longer the period, the more energy a swell has, resulting in larger and stronger waves. Often called groundswells, long-period swells are typically generated by powerful storms far from shore.

Shorter periods — frequently referred to as wind swells — cause smaller, choppy waves and are caused by windy conditions.

Some other shores could see some small wraparound during the next few days.

A reinforcing swell is expected Wednesday, maintaining advisory level surf along the Big Island’s west shores through the middle of the week and possibly into Thursday.

Elsewhere, surf along east shores is expected to remain relatively small throughout the week because of a lack of strong trade winds. A slight spike is possible today through the second half of the week as more established light to moderate east to east-southeast trades return.

Southern shorelines, meanwhile, should see a small hike in surf Wednesday when a small south swell fills in, producing some rideable waves during the second half of this week.

Visit the National Weather Service Honolulu forecast office website for additional and up-to-date weather and surf information.