A high surf warning for north and west shores from Niihau to Molokai and north shores of Maui has been extended to early Saturday morning, forecasters at the National Weather Service said today.

The warning, which had been set to expire this evening, is now in effect until 4 a.m. Saturday.

Forecasters say waves of 20 to 25 feet will continue overnight on the north and west shores of Niihau and Kauai, and the north shores of Oahu, Molokai, and Maui, while 15 to 20 foot surf is hitting west shores of Oahu and Molokai.

They warn that the large surf, “significant shorebreak, and dangerous currents make entering the water very hazardous. Anyone entering the water could face significant injury or death.”

The also warn that breaking waves may occasionally affect harbors making navigating harbor channels dangerous.