Expect windy weather with waves on most north and west shores from a declining swell, and morning showers clearing in the afternoon.

A high surf advisory is in effect for north and west shores of Kauai County, Oahu and Molokai and north shores of Maui until 6 p.m. Waves of 12 to 18 feet on north shores and 8 to 14 feet on west shores are expected to decline below advisory levels by Friday.

The waves are big enough to hold the Billabong Pipe Masters in Memory of Andy Irons surf contest at Ehukai Beach Park today.

“The swell is still holding in at the eight-to-ten foot range and there’s some good waves out there – it’s a little tough out there, but the wind is supposed to improve so we’re on,” World Surf League Commissioner Kieren Perrow said in a news release.

The weather service urges caution for beach-goers because of the large waves, shorebreak and strong currents.

Professional surfer Owen Wright had to withdraw from today’s surf contest after he suffered a head injury during a practice session Wednesday. Wright was in the hospital, but is expected to make a full recovery.

The weather service also posted a high wind advisory for Big Island summits and Haleakala, where winds of 40 to 50 mph are expected to gust to 65 mph through 6 p.m.

Lower elevations on all islands will also experience strong winds. Forecasters said east winds of 15 to 30 mph will gust to 45 mph today.

The winds were blowing in some morning showers over Oahu. The rains were expected to blow past the islands by this afternoon. But some scattered showers may still fall over windward and leeward areas.

The winds are expected to shift and become light this weekend.

Forecasters expect muggy Kona weather conditions until tradewinds return on Monday.

Daytime heating may bring some afternoon showers to leeward areas over the weekend, especially on Sunday, forecasters said.