Another nasty air, 100+ day in Tri-Cities. How long will the smoke and heat last?

The Tri-Cities air quality was rated unhealthy for all people on Tuesday, an improvement from the rating on Monday.

Air quality alerts, issued by the Washington state Department of Ecology and the National Weather Service, are in effect until noon Thursday, with the Department of Ecology alert covering all of Eastern Washington.

Monday afternoon in the Tri-Cities air quality improved from a rating of “very unhealthy” to “unhealthy.”

In the evening enough smoke had lifted to give the air quality a rating of “unhealthy for sensitive groups,” which continued into Tuesday morning, but pollution worsened after daylight.

By 9 a.m. the air quality was rated as unhealthy for everyone in the Tri-Cities, with the same rating for Mesa in Franklin County, Sunnyside and Walla Walla.

Smoky air will persist in the Tri-Cities until Thursday when the wind could shift to the southwest and a slight chance of showers is forecast by the National Weather Service.

Over the last several days, smoke has drifted into the Tri-Cities from the Green Ridge Fire burning in the Blue Mountains of the Umatilla National Forest east of Walla Walla.

The Department of Ecology posted on the Washington Smoke Blog that the weather system forecast to arrive Thursday should bring rain to many parts of the state and enough wind to push out smoke.

Cleaner air should be observed Thursday afternoon with more improvement into Friday, it said.

Ozone also was an issue in the Tri-Cities on Monday, with air quality due to just the ozone rated as “unhealthy” for several hours that afternoon.

The Tri-Cities is under a heat advisory through Wednesday, with hot weather increasing the likelihood that ozone could spike again.

Pollutants, including car exhaust, bake in the sun to produce ozone that is trapped near the ground where people breath it. Ozone can be pushed higher as northerly winds dam up pollutants at the Horse Heaven Hills, allowing them to heat up in the sun.

Winds are expected from the northeast or northwest through Wednesday night in the Tri-Cities.

Weather forecast

The weather service forecast called for a high of 103 Tuesday and 100 Wednesday in the Tri-Cities, with overnight lows in the low 70s.

The temperature should start to drop Thursday, with highs mostly in the mid 80s through Friday. Normal average highs for the Tri-Cities in August are about 90.

When air quality is rated as unhealthy for all people, more people than usual will have breathing problems or worsened symptoms of existing lung or heart disease, according to the Washington state Department of Ecology.

People sensitive to smoke, including children, seniors and people with chronic health conditions or who have had a stroke should stay indoors.

Everyone should limit time spent outdoors, if possible.

This story was originally published August 3, 2021 at 10:22 AM.