Update: High surf advisory for north-facing shores of Kaua‘i, Ni‘ihau in effect through today
Update at 7:42 a.m. Nov. 21: The high surf warning that was in effect for north-facing shores of Kaua‘i and Ni‘ihau and the high surf advisory previously issued for west-facing shores of both islands have been canceled; however, a high surf advisory for north-facing shores of the two islands is now in effect until 6 p.m. today.
The National Weather Service in Honolulu says the large north-northwest swell that brought warning level surf Monday will transition out of the north today and continue to diminish for the next couple of days. Large breaking waves of 15 to 20 feet, becoming 12 to 16 in the afternoon, are possible along northern shorelines.
Strong breaking waves and strong currents will make swimming dangerous in the advisory locations. The public should heed all advice from ocean safety officials. When in doubt, don’t go out.
Update at 4:04 p.m. on Sunday: A high surf warning was issued for west-facing shores of Ni‘ihau and north- and west-facing shores of Kaua‘i.
A large north-northwest (340 degrees) swell will rise rapidly tonight and early Monday, bringing dangerously high surf to exposed north-facing shores, and high surf to west-facing shores. The swell will gradually diminish and turn more northerly on Tuesday.
Wave heights at NDBC buoys 51001 and 51101 northwest of Kaua‘i rose nearly 9 feet in two hours Sunday afternoon, thus a rapid increase in wave heights can be expected tonight.
Original post: The National Weather Service in Honolulu has issued a special marine warning for the Kauai Channel and leeward and windward waters of the island until 1:30 p.m.
At 11:32 a.m., a cold front with heavy showers capable of producing waterspouts was located near FAD Buoy CK, or 12 nm southeast of Poipu, moving east at 25 knots.
Waterspouts and wind gusts of 34 knots or greater are anticipated. Waterspouts can create locally hazardous seas. Small craft could be damaged in briefly higher winds and suddenly higher waves.
Locations impacted include FAD Buoy CK, FAD Buoy Z, and FAD Buoy WK.
Those headed out to sea should prepare for gusty winds, steep and fast-building seas, and blinding downpours. Stay low or go below, and make sure all on board are wearing life jackets.