The National Weather Service has issued a high-surf warning for the north- and west-facing shores of O'ahu, the Big Island, Maui, Kaua'i, Moloka'i, and Ni'ihau, as well as for the north-facing shores of Maui and the east-facing shores of O'ahu.

The service said a start far northwest of the islands is expected to bring a very large, long-period swell to the islands later today. The swell, described as "dangerous," is expected to last at least through Monday.
Surf along north- and west-facing shores of Kaua'i and Ni'ihau and north-facing shores of O'ahu, Moloka'i and Maui are expected to rise rapidly this afternoon, reaching heights of 30 to 40 feet tonight and Sunday.
Other affected areas could see surf as high as 25 feet.