Spokane’s air should clear on Wednesday

A change in wind direction should improve the air quality in Spokane on Wednesday, a day after a brown cloud – considered unhealthy for everyone – settled over the city.

The air pollution for a short time Tuesday was slightly worse than a memorable episode last Aug. 21 that also was caused by regional wildfires, and matched a record that had stood since 1999.

National Weather Service forecasters said winds will shift Wednesday through Thursday night, sending smoke from the Hart Road fire in Lincoln County west into the Columbia Basin.

Coeur d’Alene could see wind gusts to 21 mph on Wednesday. Light winds are likely in the Post Falls and Spokane areas, forecasters said.

On Tuesday, conditions steadily improved after air quality hit the unhealthy category early in the morning. Readings at 4:15 p.m. showed smoke concentrations were in the moderately polluted range.

The most severe smoke pollution in the morning was on the North Side at the monitoring station near Wellesley Avenue and Monroe Street. There, the air quality index reached a peak of 172 at 9 a.m., pushing into the category of unhealthy for everyone.

An episode of severe, wildfire-caused pollution last summer hit 171 on the same scale.

Until Tuesday, the Spokane Regional Clean Air Agency hadn’t recorded such high concentrations of fine “smoke-sized” particles since 1999, spokeswoman Lisa Woodard said. She noted that health standards have changed since then, affecting air quality calculations.

Those with health issues such as asthma should avoid prolonged exposure when pollution levels are on the rise, officials said.

Officials at the clean air agency said they expected the threat from concentrations of fine smoke particles to last until Thursday at least.

Nighttime and early morning temperature inversions – cold air at the ground beneath warm air aloft – trapped smoky air near the surface on both Monday and Tuesday mornings. Warming daytime temperatures allowed the smoky air to rise so it could be moved away by the light winds on Tuesday.

The Idaho Department of Environmental Quality said air quality was good Tuesday afternoon. Smoke pollution was more severe on Monday morning in the Coeur d’Alene area.

In Spokane, highs should reach the middle 70s on Wednesday and then increase to near 80 on Thursday through Friday under sunny skies.

Stronger southwest winds could return by Saturday along with an increase in cloud cover as a new cold front reaches the Inland Northwest.