A high surf advisory has been issued for the north- and west-facing shores of Niihau, Kauai, Oahu, Molokai and Maui, effective through 6 a.m. Wednesday.

Weather officials say a northwest swell will peak late today, bringing surf of 12 to 18 feet along the north- and west-facing shores of Niihau and Kauai, and the north facing shores of Oahu, Molokai and Maui. Surf is expected to reach 8 to 12 feet along the west-facing shores of Oahu and Molokai.

Impacts are moderate. Expect strong, breaking waves, shore break and strong currents, making swimming difficult and dangerous, officials said. The public should exercise caution and heed all advice from ocean safety officials.

Forecasters, meanwhile, say a cloud band associated with a dissipated cold front near Kauai will drift over Oahu later this morning, bringing scattered showers along north- and east-facing slopes. Light showers will favor windward and mauka areas of all isles through Thursday.

Moderate trades return today as high pressure builds north of the state, but are expected to break down again from Friday into the weekend as another cold front approaches from the northwest.