Wildfire smoke returned to the Spokane region Tuesday and is expected to hover in the air through Wednesday.
Air quality in Spokane went from the good to the moderate range on Tuesday afternoon, but that was due to a layer of ozone in the lower atmosphere.
Monitors for smoke pollution were all in the good range.
The air quality forecast called for moderate pollution on Wednesday.
The smoke pollution is nowhere near as serious as the stretch of smoky days that kicked off the month of August, sending monitors into the unhealthy category on six days and the unhealthy for sensitive persons on five other days from Aug. 2 through 12.
Matt Fugazzi, forecaster for the National Weather Service in Spokane, said the smoke aloft was coming from fires in the Oregon Cascades.
The smoke that plagued the area in early August came mainly from fires in British Columbia, and was held at ground level by the weather conditions back then, he said.
“It’s not coming out of Canada like before,” he said.
The late Tuesday afternoon weather observation from Spokane International Airport indicated that there was a layer of what appeared to be smoke at about 10,000 feet in elevation, Fugazzi said.
“There is plenty of smoke out there but it’s going to stay up in the atmosphere,” he said.
Most of the smoke is going to stay at that elevation through Wednesday, he said.
The forecast for Spokane called for haze on Tuesday night and Wednesday before a cold front crosses the region on Wednesday night into Thursday.
Spokane should see a high of 88 Wednesday prior to the cold front.
By Thursday, the high temperature will drop to 82 degrees and stay in the lower 80s through Friday before temperatures warm back up to the middle 80s and lower 90s over the weekend.
Fire danger will increase on Wednesday night and Thursday.
The cold front may initially trigger isolated thunderstorms and then cause winds to increase Thursday.
Low humidity, heat and wind add to fire danger, but the conditions are not expected to be severe enough to warrant fire danger warnings from the weather service, Fugazzi said.
Thunderstorms should be isolated, he said.
The wind associated with the cold from will provide what Fugazzi described as a “good scrubbing” of smoke from the atmosphere in the region.
Subscribe to the Morning Review newsletter
Get the day’s top headlines delivered to your inbox every morning by subscribing to our newsletter.