An early season northwest swell has arrive and will produce surf of 5 to 8 feet today along north-facing shores on O'ahu, the National Weather Service said.

Elsewhere, expect surf of 2 to 4 feet along west- and south-facing shores and 1 to 3 feet along east-facing shores.

Outlook through Sunday, Sept. 21: No advisory level surf is expected through the forecast period. The current northwest swell will slowly lower into Wednesday as the swell period gradually becomes shorter.

A second northwest swell is expected to arrive late on Wednesday, peak early Thursday, then slowly lower into the weekend with the swell becoming more northerly in direction with time.

A third northwest swell is expected to arrive late Friday or Friday night, and will likely peak on Saturday, before slowly lowering into Sunday.

A series of small south swells is expected throughout the week with heights mainly just above background levels. The light trade winds will keep surf rather small along east-facing shores, however there may be some locally higher waves at locations that are exposed to northerly swell wrap.