Adam Spencer, The Triplicate

'Actually critical to stay off the jetty,' NWS warns

There is a weekend threat of extreme wave conditions approaching 20 feet in height for the coasts of Del Norte, Humboldt and Mendocino counties, and the Coast Guard discourages any activities on or near the water.

A front was expected to approach Northern California waters Friday "with south winds increasing significantly after midnight, building short-period steep seas," according to the National Weather Service.

These are not sneaker waves, said Troy Nicolini of the National Weather Service office in Eureka, but "just really big waves."

This weekend's waves have the potential to reach high on shoreline rocks and jetties, making it all the more important to stay away from the water, Nicolini said.

"This is a weekend where it's actually critical to stay off the jetty in Crescent City," Nicolini said.

The waves are being generated by storms several hundred miles off the coast, but "we have a local storm as well, which will make the ocean particularly bad," Nicolini said.

The winds are predicted to peak this morning, rapidly decrease and then shift to northerly winds by tonight.

Waves are predicted to build to near 18-20 feet early Sunday.

The marine forecast south of Point St. George includes a gale warning in effect from last night through this morning.

Today is expected to bring southwest winds of 17-29 mphwith gusts up to 46 mph. South waves of 11 feet at eight seconds are predicted with west waves of 13 feet at 13 seconds.

Sunday is expected to bring east winds of 5 mph with 18 foot west waves at 16 seconds.

The combination of winds from different directions makes for a "confused ocean" that is difficult to navigate, Nicolini said.

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