Strong and gusty northeast winds that could damage trees, power lines and roofs are expected to blow through the state this afternoon through Sunday, the National Weather Service said.
Building high pressure in the wake of a weak frontal system is expected to funnel and accelerate winds between the islands and down leeward slopes of mountain areas, leading to much stronger than normal trades, the weather service said.
The weather service posted a high-wind watch beginning this afternoon and running to Sunday afternoon. Winds are expected to blow 34 to 45 mph with localized gusts of more than 65 mph. The highest sustained speeds and gusts are likely over leeward slopes.
The high winds could damage trees, power lines and roofs, the weather service warned. Those planning outdoor activities should keep in mind that tents and tarps could be damaged. People also should secure or take down loose outdoor objects prior to the windy weather.
The National Weather Service also has posted a high-surf advisory and marine advisories this weekend.
The high-surf advisory that runs through 6 a.m. Monday affects north, east and west-facing shores of Molokai and north and east facing shores of Maui.
Surf is expected to be 14 to 18 feet on north-facing shores and 8 to 12 feet on west-facing shores. It was expected to peak Friday night and today and begin to diminish Saturday night.
The surf will bring strong shore break and rip currents making swimming dangerous.
A small-craft advisory was in effect until 6 a.m. today, and a gale watch was posted this morning through Sunday night. A gale watch is issued when the risk of gale-force winds of 39 mph to 54 mph has significantly increased but the specific timing and location remain uncertain. It is meant to provide mariners lead time to prepare for the rough sea conditions.
Beginning this morning, northeast winds are expected to blow 40 mph to 46 mph with rough seas up to 21 feet.
The forecast for today is mostly cloudy and very windy with scattered showers. High temperatures will be from 78 to 83 degrees with lows of 65 to 70 degrees.
Sunday is expected to be partly cloudy and very windy with scattered showers over windward and mountain areas and isolated showers over leeward areas. Highs should hit 76 to 81 degrees with lows of 65 to 70 degrees.