A high surf warning has been issued for north and west facing shores of Hawaiian isles from Niihau to Maui through 6 p.m. on today.

The National Weather Service says a large, northwest swell is expected to build down the isle chain throughout today, leading to warning level surf through Thursday.

Surf is expected to build to 18 to 25 feet along north and west shores of Niihau and Kauai, and north shores of Oahu, Molokai, and Maui by this afternoon.

Surf along west shores of Oahu and Molokai will build to 15 to 20 feet by this afternoon.

Officials warn of large, breaking surf, significant shore break and dangerous currents, making entering the water very hazardous. Anyone entering the water could face significant injury or death.

Ocean water may also sweep across portions of beaches, and breaking waves may occasionally impact harbors, making navigating the harbor channel dangerous.

Today’s forecast, meanwhile, is mostly sunny, with isolated showers, highs from 80 to 85 degrees Fahrenheit and variable winds up to 15 miles per hour. Tonight’s lows are from 66 to 71 degrees.

Forecasters say today’s weather should remain mostly dry, with light tradewinds. A front approaching from the northwest, however, is expected to bring clouds and showers to Kauai late Thursday.

By Friday, the clouds and showers are expected to hit windward and mauka areas of all Hawaiian isles, a pattern that will continue through the weekend.

The first record high of December was recorded on Tuesday in Kahului, where a high of 89 degrees surpassed the previous record of 87 set in 1995.