An extra-large northwest swell will be slow to diminish Thursday per the National Weather Service, then shift to the north tonight and Friday as it gradually eases.

Another powerful, but smaller, very long-period northwest swell is expected Saturday through Monday, with peak surf heights approaching High Surf Warning values.

After this long-lived swell eases, surf heights early next week look to remain below advisory levels along all shores as moderate-sized northwest swells arrive.

A tiny south swell is possible this weekend.

Nuy Cho is the executive producer of Spectrum News Hawaii. She writes the surf report and covers other general news. Read more of her stories here.