Hurricane Hector to stir dangerous building surf in Hawaii this week

By Faith Eherts, AccuWeather meteorologist

August 06, 2018, 8:15:08 PM EDT

Major Hurricane Hector, a Category 4 storm as of Monday, is expected to continue its steady trek over the Pacific Ocean south of Hawaii this week.

Hurricanes that track in from the east typically encounter cooler waters near Hawaii and weaken before reaching the islands. The most destructive hurricanes to hit Hawaii, such as Iniki in 1992, have typically approached the islands from the south.

However, the waters surrounding Hawaii are currently warmer than normal.

While Hector will be past peak intensity when it impacts the islands at midweek, it is still expected to be a hurricane.

AccuWeather meteorologists expect Hector to pass well south of Hawaii, including the Big Island. 

However, there will be a significant impact related to seas and surf on many areas.

Some residents and tourists may notice a change in the weather as well by midweek.

"Hector is expected to pass far enough to the south so that no important wind issues are expected to impact the Big Island," according to AccuWeather Hurricane Expert Dan Kottlowski.

"However, very rough surf is expected to impact mostly south- and east-facing coastal areas of the Big Island," Kottlowski said. "There will also be an increase in surf over the rest of the Hawaiian Islands during Wednesday through Friday."

An uptick in squalls with locally drenching rain and brief gusty winds will increase across the Big Island first, then perhaps Maui, Moloka'i and O'ahu during the latter part of the week.

Large swells, rough seas and strong rip currents will impact mainly east- and south-facing coasts. Swimming and boating will become dangerous later this week, and it will be important to heed local warnings, advisories and beach postings.

In lieu of tropical storms, near-shore waves on the south-facing shores of the islands tend to average 2-3 feet.

"Near-shore frequent waves along the south- and east-facing coastal areas are likely to build to 6-10 feet with occasional higher waves," according to AccuWeather Senior Meteorologist Alex Sosnowski.

Offshore to the south, hurricane conditions are expected with frequent waves building to 10-16 feet with occasional higher waves topping 20 feet.

"The biggest waves will be along the south- and southeast-facing coastline of the Big Island," Sosnowski said. "However, a significant uptick in waves on the south-facing shorelines and north-south channels between all of the islands in the Hawaiian chain are likely as the week progresses."

Dangerous surf may occur surrounding much of the islands during the middle and latter part of this week.

Travel by boat will be impacted, potentially spoiling vacation plans and perhaps limiting inter-island travel for a time.

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AccuWeather East Pacific Hurricane Center

Southeastern areas of the Big Island have been devastated by the eruption of the Kīlauea Volcano and the lava flows that followed, but AccuWeather Meteorologist Jim Andrews anticipates minimal added hazards to the region due to Hector.

"While showers can be enhanced at midweek as the hurricane passes by to the south, the risk of acid rain being produced as the downpours hit the steaming lava would seem to be low," he said.

Additionally, Hector’s winds will whisk vog and laze toward the southern tip of the island and then out to sea.

By the time the weekend rolls around, Hector’s impacts on Hawaii are expected to be over.

Elsewhere in the eastern Pacific, tropical systems John and Ileana are spinning just to the southwest and south of southern Mexico, respectively.

AccuWeather will continue to provide updates on Hector and other tropical activity around the globe. Download the free AccuWeather app to stay alert to weather hazards for your area.

With the potential for an El Niño developing into this autumn, warmer-than-average water temperatures over the tropical Pacific could result in more threats than average for the Hawaiian Islands.

On average, there are approximately five tropical systems per year over the central Pacific basin.