Two major wildfires expand in Northern California and central Oregon

Two major wildfires in Northern California and central Oregon continued to expand on Sunday under a blistering heat wave and dry conditions, prompting thousands of evacuations and sweeping air quality advisories as firefighters labor to halt the blazes near communities and critical wine country infrastructure.

In Napa County, the Pickett Fire had grown to about 6,800 acres and remained roughly 11 percent contained as of Sunday, with authorities ordering about 150 residents from their homes and placing another 360 under evacuation warnings. The blaze, which began in the days of extreme heat, was burning near Aetna Springs and Pope Valley, threatening some 500 structures as crews worked through rugged terrain with extensive ground and air support. More than 1,230 firefighters were on scene, aided by 10 helicopters, bulldozers and hand crews. The fire is under investigation, and officials say the weather continues to complicate containment efforts.

The Pickett Fire also raises concerns beyond property loss. The Napa Valley wine region, home to hundreds of wineries, faces the risk that smoke could affect grape crops. Local winemakers expressed worry that smoke taint could alter...