‘Giant surf’ can cause damage and endanger anyone who attempts to enter the waters along the northern and western coasts of the Hawaiian Islands into Monday.
Swells from a powerful storm over the northern Pacific Ocean are propagating southeastward and bringing a dramatic increase in the surf around Hawaii.
The surf will peak from northwest to southeast late Sunday into Monday morning.
At that time, latest projections from the National Weather Service (NWS) in Honolulu indicate that the northwest swells can produce waves of 40 to as high as 50 feet in the surf zone along the north-facing shores of the Hawaiian islands, along with the west-facing shores of Ni’ihau and Kauai.
Such wave heights match the definition of ‘giant surf’ by the NWS.
In addition to the sheer magnitude of the surf, gusty winds driving the ocean water onshore can lead to coastal inundation and beach erosion in low-lying areas that face north throughout the island chain.
West-facing locations of the western islands are also at risk.
The most significant coastal flooding can be anticipated around and shortly after midnight, local time, early Monday morning, near when the highest astronomical tide cycle of the month will occur.
The pounding seas can damage boats, docks and other weaker buildings in marinas and harbors, including the Haleiwa Harbor.
Overwash may force officials to close some coastal roads for a time.
“The Honolulu Department of Emergency Management strongly urges all residents, visitors and ocean and beach goers to avoid affected north and west shores until this high-surf event subsides, and to heed the instructions of Ocean Safety lifeguards, other first responders, and law enforcement personnel,” according to a statement from the City and County of Honolulu.
This event is not expected to rival the extreme high surf that was produced when the powerful Kona low slammed Hawaii and left one person dead around Feb. 10.
While not to the severity of what is expected the next couple of days, another swell from the northwest may bring another period of rough surf to the island chain at midweek.