Dangerous surf, with waves topping out at up to 45 feet, are expected today on Oahu’s North Shore.

Forecasters also expect southerly wind to blow vog back over the islands tonight. The volcanic haze is likely to last into the weekend.

The National Weather Service has posted high-surf warnings for the north and west shores of Oahu, Kauai County and Molokai, and the north shores of Maui.

“Heights are expected to reach giant levels” of 35 to 45 feet on north shores by this afternoon and west shores of Kauai County, the weather service said.

“These dangerous conditions mean that only highly experienced persons should enter the water,” the weather service said. “Inexperienced persons should remain off beaches and adjacent beachfront areas. Large breaking surf, significant shorebreak and dangerous currents make entering the water very hazardous. Anyone entering the water could face significant injury or death.”

The high-surf warning is expected to remain in effect until at least 6 p.m. Thursday.

The Weather Service said the high surf could surge across beaches and affect coastal properties and roadways.

The forecast for Honolulu and the South Shore of Oahu calls for sunny to partly cloudy skies and hazy conditions through Saturday.

Highs should be about 81 degrees with lows between 61 and 71 degrees.

Tradewinds could return Saturday night, bringing some relief from the vog.