Update: Thunderstorms trigger special marine warning for leeward waters of Kauaʻi near southern tip of Niʻihau

Update 12 a.m. Dec. 16, 2025: A special marine warning has been issued for Kauaʻi leeward waters until 2 a.m. Tuesday.

A thunderstorm capable of producing waterspouts was located 7 nautical miles northeast of the southern tip of Niʻihau, or 20 nautical miles southwest of Barking Sands moving northeast at 10 knots at 11:53 p.m. Monday night.

Thunderstorms can produce waterspouts, which can easily overturn boats and create locally hazardous seas. Wind gusts of 34 knots or greater and sudden high waves could damage small craft.

A flood watch is also in effect for all of the island of Kauaʻi until 6 a.m. Tuesday.

The public is advised to stay away from streams, drainage ditches and low lying areas prone to flooding.

Update 4 p.m. Dec. 15, 2025: The high surf advisory remains in effect for north-facing shores of Kauaʻi and Niʻihau until 6 a.m. Tuesday.

A large-period swell of about 350 to 360 degrees in the north is building in area waters this afternoon. Elevated surf is expected along north facing shores through tonight.

According to the National Weather Service, large breaking waves of 14 to 18 feet are expected to subside to 10 to 15 feet later tonight.

Ocean Safety Bureau officials are advising no swimming or other ocean activities at Hanalei Bay and all north-facing shores due to high surf and hazardous ocean conditions.

County lifeguards advise no recreational water activities along all north-facing shores. As a safety precaution, ocean safety officials have posted warning signs and are monitoring the area.

For updated information on ocean and weather alerts, visit the National Weather Service website.

For up-to-date information about Kaua‘i ocean conditions and ocean safety, speak to a county lifeguard at any lifeguard station, or visit the Ocean Safety Bureau website.

Original 7:45 a.m. Dec. 14, 2025: A high surf advisory is in effect for the north- and west-facing shores of Ni’ihau and Kaua’i as a moderate to large west-northwest swell increases across the region, according to forecasters with the National Weather Service.

The advisory takes effect at noon on Dec. 14 and will remain in place until 6 p.m. on Dec. 15.

A medium-period swell from about 300 degrees is expected to build through the morning, with surf peaking Sunday evening before gradually subsiding on Monday afternoon.

Officials with the National Weather Service added that surf heights are expected to reach 12 to 16 feet along north-facing shores and 8 to 12 feet along west-facing shores of both islands.

Ocean safety officials warned that strong breaking waves and powerful currents will create hazardous conditions, making swimming dangerous. The impacts are considered moderate but could pose a risk to anyone entering the water, especially in exposed areas.

Officials urged residents and visitors to use caution and follow guidance from ocean safety authorities. As a general rule, authorities advised, if conditions appear unsafe, stay out of the water and only swim at beaches with towered lifeguards.