UPDATE: 4 p.m.

The high surf advisory has been expanded to include the north-facing shores of Maui and the west-facing shores of Lanai and Hawaii island until 6 p.m. Wednesday.

The advisory remains in effect for the north- and west-facing shores of Oahu, Kauai, Molokai and Niihau.

Expect surf of up to 12 feet along the west shores of Lanai as well as 6 to 8 feet growing to 7 to 10 feet on Tuesday along the west shores of Hawaii island.

“Several pulses of west-northwest (300 degrees) swell will arrive over the next couple of days,” forecasters said. “A medium-period swell today will be followed by a larger swell arriving tonight into Tuesday that will produce advisory to near warning level Tuesday through Tuesday night. This swell will then gradually diminish on Wednesday.”

EARLIER COVERAGE

A high surf advisory is in place for the north- and west-facing shores of smaller isles in Hawaii through 6 p.m. Wednesday.

The National Weather Service expects the current west-northwest swell to peak today, followed by an even larger one on Tuesday that will keep high surf in place through Wednesday evening.

The high surf advisory covers:

>> North-facing shores of Niihau, Kauai, Oahu, and Molokai, with surf of 12 to 18 feet today.

>> West-facing shores of Niihau, Kauai, Oahu, and Molokai, with surf of 8 to 12 feet today.

Forecasters expect surf to climb even higher after a larger swell arrives Tuesday, boosting the advisory close to warning levels, and an expansion of the advisory to parts of Maui and Hawaii island as well.

Strong, breaking waves and strong currents on affected shores will make swimming dangerous.

“Heed all advice from ocean safety officials,” forecasters said. “When in doubt, don’t go out.”

Surf along south-facing shores, meanwhile, is expected to decrease from 4 to 6 feet today to 3 to 5 feet Tuesday morning. Surf along east-facing shores is expected to remain small, at flat to 2 feet today and Tuesday.

Forecasters also expect “breezy, southwest conditions” and “more overcast showery weather” over Kauai and Oahu today, as several dissipating fronts move southeast down the island chain.

Southwest winds may become gusty at times along north- and east-facing areas due to downslope effects.

A high wind warning is in effect for Big Isle summits until 6 p.m. today due to west winds of 50 to 60 mph, with localized gusts over 70 mph.

Travel to the summits should be postponed until conditions improve.

A small craft advisory for Oahu leeward waters, Kaiwi Channel, and Maui County windward waters, remains in effect until 6 p.m. Tuesday.