Windstorms that pummelled parts of Washington state and Oregon over the weekend have left hundreds of thousands of people without electricity, officials said on Sunday.

The storm brought winds that registered gusts of about 96km/h at Sea-Tac Airport in Washington, the National Weather Service in Seattle said.

Puget Sound Energy reported about 218 000 of its customers had no power as of 06:00 on Sunday. Some could be without power for "multiple days," the utility said on its website.

Other utilities in Washington also reported outages, KOMO reported .

Thousands were also without power on Sunday morning in parts of Oregon after the strong winds downed trees, KOIN-TV reported .

Alaska Airlines said it grounded all its flights between 04:20 and 05:15 on Sunday after a power outage in the Seattle area, where its operations are based.

Airline spokesperson Oriana Branon said the power went out around 03:30 and came back on about an hour and a half later.

She said 27 flights were delayed and five were cancelled. Inconvenienced customers were being offered compensation on a case by case basis, she said.