A high surf advisory has been issued for the north and west shores of all isles from Niihau to Maui, in effect from 6 p.m. today through 6 p.m. Saturday.

The National Weather Service says a large, northwest swell will build today, peak tonight and Saturday before gradually lower the rest of the weekend.

Surf along north and west shores of Kauai County, and north shores of Oahu, Molokai, and Maui is expected to build to 14 to 18 feet tonight and hold through Saturday.

Surf along west shores of Oahu and Molokai will build to 8 to 12 feet tonight and hold through Saturday.

Officials warn of strong, breaking waves, and rip currents, making swimming difficult and dangerous, and to heed all advice from ocean safety. Boaters should watch out for recreational surfers and bodyboarders using harbor channels to access surfing areas.

Today’s forecast is mostly sunny, with highs from 83 to 88 degrees Fahrenheit and variable winds of 15 mph. Lows tonight range from 68 to 73 degrees.

Forecasters said moderate tradewinds will return later today and become locally breezy by early next week.

Fair weather is also expected over the weekend, other than a few passing showers for the windward and mauka areas.

A small craft advisory has also been issued for all northwest, windward and leeward Kauai waters, along with Kauai and Kaiwi channels, and windward Oahu and Maui waters, from 6 p.m. today through 6 p.m. Saturday.