As wildfires gnawed on forests across the Pacific Northwest on Friday, dry, hot, breezy weather was heightening the risk that the fires would spread and new ones would ignite, and the dangerous conditions were expected to continue through the weekend.

The critical wildfire threat on Friday was focused over southeast Oregon and small portions of Northern California and Nevada. On Saturday, the risk expands to include all of eastern Oregon and Washington and into northeast California, northwest Nevada and north Idaho and Montana.

Red flag warnings were in effect across the region for Friday and Saturday, with 90-degree heat, wind gusts over 30 miles per hour and relative humidity levels in the teens, or even the single digits, in the forecast.

Much of the threatened region is forested and mountainous, but on Saturday it will include urban areas such as Bend, a city in central Oregon, where some of the most active wildfires in the country scorched the landscape and blanketed valleys in smoke on Friday.

Nearby, the Akawa Butte fire burned outside Sisters, a small town that is a popular summer destination for outdoor recreation. The Oregon State Fire Marshal called it “the nation’s highest-priority fire for resource allocation,” and on Friday the number of firefighters assigned to the blaze doubled to nearly 1,200.

Gert Zoutendijk, a spokesman for the fire marshal, said that with this fire, a lot of “values are at risk, which include homes and lives and infrastructure.”

Forecasters warned that the fire danger this summer would be high in this drought-plagued corner of the country. A thin layer of snow blanketed the mountains of the West last winter, particularly the Cascades, and the vegetation has dried out more quickly than normal without the moisture from the melting snow that typically lasts into at least early summer.

“The lack of winter snowpack is definitely having an effect,” said Jim Wallman, a meteorologist at the National Interagency Fire Center in Boise.

The predictions materialized across Oregon and Washington this month, particularly after thunderstorms raced across the state a week ago and delivered thousands of lightning strikes but little rainfall. More than 140 new fires started across two days, and a second thunderstorm brought more lightning and more fires earlier this week.

As of Friday, 92 large fires have been reported in the two states since Jan. 1. At this time last year, there had been 45 large fires. A timber fire is considered large when it reaches 100 acres, and a fire in grass gets the designation at 300 acres.

“So basically we’ve had double compared to last year,” said Carol Connolly, a spokeswoman for the Northwest Interagency Coordination Center.

The fire threat comes after several days of hot weather left trees, shrubs and grass desiccated and highly flammable. On Friday, winds were picking up, with an area of high pressure spread across the Western United States and an area of low pressure just off the coast of the Pacific Northwest. Winds were also predicted to blow on Saturday.

“There’s a pressure gradient, and the wind wants to blow from high pressure to low pressure,” said Bryan Jackson, a meteorologist with the Weather Prediction Center. “It’s not an extreme crazy wind, but you’ve already got fires, and it doesn’t take much wind for them to spread.”

A slight improvement with cooler weather was expected Sunday, but there will still be a fire threat.