A small craft advisory remains in effect for Hawaii Island waters until 6 p.m. Thursday, according to the National Weather Service in Honolulu.
The service forecast southwest winds of 15 knots to 25 knots, or about 17 mph to 29 mph, with gusts reaching 35 knots of 40 mph. Rough seas of 7 feet to 21 feet are also expected. The strong winds and rough seas are associated with a cold front and an extremely large northwest swell.
Forecasters, in a marine weather statement, also cautioned that the northwest swell will affect Hawaii harbors through Thursday night. Large breaking waves and harbor surges should be expected at harbors along north- and west-facing shores, including Honokohau and Hilo harbors.
A small craft advisory means that wind speeds of 25 to 33 knots, or 29 to 38 mph, and/or seas are expected to be 10 feet or greater and expected to produce conditions hazardous to small craft, according to the service. Inexperienced mariners, especially those operating smaller vessels, should avoid navigating in such conditions.