A large west-northwest swell will generate 20- to 30-foot surf with larger sets on north and west shores of Kauai and the north shores of Oahu, Molokai and Maui.

The National Weather Service has issued a high surf warning from 4 p.m. today to 6 p.m. Saturday.

Sets off of Kauai and Niihau could reach 30- to 35-feet, forecasters said.

But organizers of the Quiksilver in Memory of Eddie Aikau surf contest, which is only held when waves are consistently 25 feet and higher at Waimea Bay, said the contest will not be held.

“We are expecting it (the surf) to fall well short due to the very westerly angle and shadowing from Kauai and Niihau,” said Jodi Wilmott, a spokeswoman for the contest, which was last held in 2009.

The Kona and Kohala coasts will also see warning level surf later tonight because of the unusual westerly direction of the swell.

A high surf advisory is also posted for west shores of Oahu, Lanai and Kahoolawe, where 20- to 25-foot surf is expected.

“The swell will produce large and hazardous surf along exposed shorelines tomorrow through Friday,” forecasters said.

“Expect ocean water occasionally sweeping across portions of beaches, very strong breaking waves, and strong longshore and rip currents. Breaking waves may occasionally impact harbors making navigating the harbor channel dangerous,” forecasters said in the warning.

The currents and strong, breaking waves will make swimming dangerous, forecasters said. Beachgoers should heed lifeguards, forecasters said.

The high surf warning for the Big Island runs from midnight tonight through 6 p.m. Saturday.

The advisory for west shores of Oahu runs from 4 p.m. today through 6 p.m. Friday.

“Surf will begin building rapidly on Kauai and Niihau late this afternoon then spread eastward to Oahu Molokai and Maui tonight.,” forecasters said. The surf will ease slowly Friday afternoon and evening.”