Crews battling a flurry of wildfires raging unchecked in the Pacific Northwest braced on Thursday for high winds forecast in the region a day after three firefighters were killed and four others were injured in Washington state.

Authorities late on Wednesday ordered the evacuation of about 4,000 homes threatened by fire in the riverfront towns of Twisp and Winthrop in the Methow Valley, nestled in the foothills of the Cascade mountains in north-central Washington.

The so-called Twisp River fire has roared through 16,000 acres (6,475 hectares) of rural brush and dry timber about 115 miles (185 km) northeast of Seattle since erupting on Wednesday.