Nov 24 – UPDATE: 8:30 am
The earlier wind warning has been extended to all Hawaiian islands and extended until 6 a.m. Friday.
Northeasterly winds of up to 15 to 35 mph, with localized gusts of up to 50 mph, are expected to accompany the cold front moving down from the western end of the island chain, according to the National Weather Service.
A wind alert has been issued for the islands of Niihau, Kauai and Oahu, effective from 6 p.m. today through 6 a.m. Thanksgiving Day.
The National Weather Service said northeast winds of 20 to 30 mph with gusts of up to 50 mph are expected to accompany a cold front sweeping down the western end of the island chain tonight.
Those strong and gusty winds are likely to spread eastward across the rest of the state on Thanksgiving, forecasters have warned, with the greatest threat of gusts on ridges and leeward zones prone to downgrades.
In addition, short periods of strong gusts of wind can occur on exposed northern and eastern slopes, as well as on beaches, especially immediately after the passage of the front.
Officials warned that winds this strong can rip off shingles and knock over branches, making driving difficult, especially for drivers in high-profile vehicles.
The public should also watch for falling branches when walking or driving, secure or dismantle tents and awnings, and be prepared for power outages.
Forecasters expect a cold front to move across the Hawaiian Islands, beginning with the western islands tonight, before exiting the east-southeast island of Hawaii on Thanksgiving Day.
The system ahead of the front is expected to produce a period of locally heavy rainfall, with strong NE winds developing as it passes.
Additionally, a very large north wave is expected tonight, triggering a high surf warning for the north shores of Niihau, Kauai, Oahu, Molokai and Maui in effect until 6 a.m. Friday.
Forecasters expect dangerously large, breaking waves of 20 to 25 feet along the affected north shore.
The peak of the swell coincides with gusty northeast winds, along with high tides expected in the early hours of Thursday and Friday.
That could cause significant flooding problems and big waves along north-facing coasts, officials said.
The public should stay away from affected coasts, be prepared for road closures, and delay entering or exiting channels affected by high surf.
A small craft warning and a storm warning have also been issued for various canals and bodies of water, with the former in effect until Thursday 6am and the latter from Thursday 6am to Friday 6am.
Surges are also expected in the northern ports on Maui and Hawaii starting Thursday and through the weekend. Seafarers using the ports of Kahului and Hilo should exercise caution when entering the port and when docking or launching vessels.