The large nortwest swell that rolled in over the weekend is still generating big surf for some shores, prompting weather officials to extend the high surf warning to 6 p.m. tonight.

The north and west shores of Oahu, Molokai, Kauai County, and the north shore of Maui are covered by the warning.

Surf up to 18 to 25 feet is expected along north shores, and up to 12 to 20 feet along west shores, according to officials at the National Weather Service.

Beachgoers are warned that the large surf, shorebreak and strong currents can make entering the water at affected beaches very dangerous.