A high surf warning along with peak monthly tides is expected to bring significant beach erosion to shores around the islands, the National Weather Service said.

The weather service says the high surf warning is in effect for north and west-facing shores of Niihau and Kauai, along with north-facing shores of Oahu, Molokai, and Maui. The warning is set to expire at 6 p.m. Tuesday.

Surf is expected to reach 15 to 20 feet this afternoon and 30 to 40 feet tonight through Monday before lowering to 20 to 30 feet Tuesday for the areas under the warning.

On west-facing shores of Oahu and Molokai, surf is expected to reach 10 to 15 feet this afternoon and rise to 20 to 30 feet tonight through Monday. Surf will lower to 15 to 20 feet along west-facing shores Tuesday.

The weather service said a large northwest swell is expected to fill in today and continue through midweek along north and west-facing shores. Surf will exceed warning levels late tonight and last through Tuesday, before dropping below advisory levels possibly on Wednesday.

Large surf and peak monthly tides could “lead to significant beach erosion and increase the potential for overwash along typically vulnerable coasts,” the weather service said. Peak tides are expected around daybreak.

Beachgoers should expect ocean water surging and sweeping across beaches with powerful rip currents at most beaches, the weather service said. Large breaking waves may impact harbor entrances and channels, creating difficult conditions for boaters.