Message Summary: ...high surf warning for north and west facing shores of niihau kauai oahu molokai and north facing shores of maui and west facing shores of the big island...
.a long-period northwest swell will build through the day, peak tonight and early thursday at dangerously high levels, then gradually diminish late thursday and friday.
...high surf warning now in effect until 6 pm hst thursday...
* what...surf building to 25 to 35 feet through the day along north facing shores, and 15 to 25 feet along west facing shores.
* where...north and west facing shores of niihau, kauai, oahu, and molokai, and north facing shores of maui.
* when...until 6 pm hst thursday.
* impacts...high. Expect ocean water occasionally sweeping across portions of beaches, very strong breaking waves, and strong longshore and rip currents. Breaking waves may occasionally impact harbors making navigating the harbor channel dangerous.
* additional details...there will likely be long lulls between the sets of larger waves as the swell builds today. Don`t be caught off guard when larger waves arrive suddenly.