Montana Public Radio

Western Montana Air Quality Expected To Worsen Dramatically Over The Weekend

Sep 12, 2020

Smoke from the west coast continues to move into Montana and is expected to bring "very unhealthy" and hazardous" air quality to parts of the state this weekend.

This update from Missoula City-County Health Department Air Quality Specialist Sarah Coefield was posted on September 12 at 6:23 p.m.

"Good evening, I thought you might want a status update on the upsettingly large smoke plume that's forecasted to hit us tomorrow. Ready? It's still coming. 

"Oh, you want more? Okay. Today, the giant plume of smoke spread out over Washington, creating Very Unhealthy and Hazardous air quality in the eastern part of the state. The smoke has been slowly inching its way our direction and is currently partially in Idaho. A northern section has already made its way into northwest Montana, and air quality in Libby and Thompson Falls has rapidly deteriorated. (In fairness, Libby's air quality may also be taking a hit from the Callahan Fire, which has been pretty active today. The air quality in Thompson Falls is Hazardous. It's been hit with the smoke that's coming our way, which is bad news for those of us who enjoy breathing air.)

"If you check out the satellite, you can see there's a lot going on. I recommend you visit this link to the GOES 16 satellite to see the smoke movement in action:  (It's hard to differentiate smoke movements from the still photo, and frankly it's amazing to see smoke moving in near-real time.)

"The smoke we're most concerned about is at ground level and is blanketing Oregon and Washington. It looks like a partially cooked marshmallow that you dropped in the dirt and then stepped on. You know - gross and kind of sludgy. Above that layer, there is smoke higher up in atmosphere arcing across the Northwest. The smoke that's higher up is already above us, which is why the sky isn't what any of us would really consider blue, right now. Happily, that smoke is high overhead and isn't really affecting our air quality. (Air quality is currently Moderate across Missoula County.) Meanwhile, the fires in Idaho have had an active day, and they are sending out plumes that are going to be visible over the Bitterroot Valley. Also, if you want extra smoke on top of your smoke, check out the fires in Oregon. A couple of them were able to send up plumes above the nasty marshmallow of sadness.

"The HRRR model has so far done a really good job predicting the day's smoke movement, so I'm feeling pretty good about the prediction of smoke rolling into the area by tomorrow morning. (And also terrible, because no one should breathe sludge.)

"There is a good chance air quality in Missoula County will be Very Unhealthy or Hazardous on Sunday. We can hope for less, but based on what we're seeing at other monitors, it is reasonable to expect significant smoke impacts in Missoula County tomorrow morning.

"If you have air conditioning, now would be a great time to think about closing your doors and windows. The air quality is going to get progressively worse overnight, and the less smoke you let inside, the better. Everyone who can, should take measures to clean their indoor air when the smoke arrives. Check out www.montanawildfiresmoke.org or my Smoke Ready blog for advice on using portable air cleaners, furnace filters or even building your own air cleaner to protect your indoor air quality.

"There's a chance the worst of the smoke will stay west and north of us. We're currently expecting to see the easternmost edge of the worst section of smoke. Whatever we do end up with will be with us for some time due to high pressure creating stable atmospheric conditions and preventing smoke from easily leaving the area."