KENNEWICK — Air quality in the Tri-Cities deteriorated Tuesday to a level considered unhealthy for sensitive people.
Smoke blew over the Tri-Cities from wildfires burning in Oregon, increasing to a level considered unhealthy for children and others by about 2 p.m.
Several fires were burning Tuesday in the Oregon Cascade Mountains, including the Bootleg Fire southeast of Crater Lake National Park that had grown to 315 square miles.
The smoky air is expected to persist in the Tri-Cities through Wednesday, according to the National Weather Service.
But then cooler air from the Pacific Ocean should push through the Cascade Mountains and clear the air in the Tri-Cities, forcing smoke toward Idaho.
However, the threat of local wildfires will increase starting Wednesday afternoon.
Red flag warning
The National Weather Service has issued a red flag warning for wildfires across southeast Washington, including all of Benton and Franklin counties, from noon Wednesday until 11 p.m. Thursday.
Low relative humidity and wind gusts up to 22 mph will create critical weather conditions for an area already in drought, according to the weather service.
Although Pacific Ocean air will cool temperatures and increase humidity, wind will keep the fire danger high until late Thursday, according to the weather service.
A heat advisory for high temperatures in the low 100s for the Tri-Cities will expire Wednesday night, with forecast highs dropping to 94 on Thursday, 90 on Friday and 91 on Saturday before they return to the high 90s through early next week.
Normal average highs for the Tri-Cities in July are about 90, according to the weather service.
When air quality is rated as unhealthy for sensitive groups, children, older adults, pregnant women, smokers, stroke survivors and people with health conditions such as diabetes, asthma and heart disease should limit time spent outdoors.
Thursday afternoon the air quality was rated as unhealthy for sensitive groups or for everyone due to smoke from Yakima east to Walla Walla.
Moses Lake air was rated as unhealthy for all people.
Ozone levels elevated
Not only smoke, but ozone was impacting air quality in the Tri-Cities on Tuesday. Ozone also was at levels considered unhealthy for sensitive groups.
In the Tri-Cities pollutants, particularly those blown by light winds from the north, dam up against the Horse Heaven Hills.
There particles bake in the sunshine on hot days, producing ozone, which spreads across the Tri-Cities.
The chemicals that create ozone can come from the exhaust of motor vehicles, a major contributor in the Tri-Cities.
Multiple fires were burning in Washington on Tuesday included a fire on the Colville Reservation that was estimated to have burned 12,000 acres and three homes, according to the Washington state Department of Ecology, posting on the Washington Smoke Blog.
The Lick Creek fire near Asotin in Eastern Washington has burned more than 55,000 acres.
The third large fire in the state is the Burbank Fire on the Yakima Firing Range, which has burned 13,000 acres. Fire crews have contained the fire at lines along Interstate 82.
