The National Weather Service this morning posted a wind advisory for sustained winds of 30 to 40 mph, with gusts to 50 mph, for all islands. The gusts may be especially intense in valleys and other spots where

winds are channeled, said Bob Farrell, the weather service's lead forecaster, who added that the warning should remain in effect at least until 8:30 tonight.

The gusts brought down a power line that was part of a 138,000-volt transmission system about two miles mauka of Newtown at 10:30 a.m. yesterday, starting a brush fire that was in turn fanned by high winds. Firefighters worked until after 5 p.m. when darkness forced them to leave the fire burning in the remote area.

Hawaiian Electric Company reported a series of failures at various locations around O'ahu.

About 20 homes in the Tantalus area were thought to have lost power at 8 a.m. when a tree fell onto a power line there, HECO spokesman Fred Kobashikawa said. Workers restored the line several hours later, but then discovered customers had been fed by an alternate circuit.

At 12:13 p.m., about 1,500 homes and businesses in the Waialua area lost power, also because of a tree on a power line. Power was restored to those homes by 5 p.m. yesterday, Kobashikawa said.

More than 225 customers in the Diamond Head and Kapahulu areas lost power at 2:12 p.m. when a line went down apparently because of a mechanical failure. Service was restored an hour later.

Another 730 customers in the Pacific Palisades area lost power at 2:16 p.m. because of a downed tree. Within 15 minutes, about 1,500 customers in the Waipahu area lost power. Those families had power restoredby 4:30 p.m.