Air Quality Update for Western Montana, August 11, 2017

Aug 11, 2017
Originally published on August 11, 2017 10:08 am

Today's air report courtesy of Missoula City-County Air Quality Specialist Sarah Coefield:

"The Canadian smoke that mixed down yesterday is still with us this morning, causing thick haze and air quality ranging from Unhealthy for Sensitive Groups to Unhealthy across most of Missoula County.

Conditions are, unsurprisingly, worst at locations near active fires. The Lolo Peak Fire hasn't been showing particularly aggressive behavior lately, but it is still consuming fuel and acreage, and creating smoke that pooled in Lolo this morning before creeping into Missoula. Florence hasn't been hit as hard as Lolo, but there is still a lot of smoke in the area.

Air quality is Unhealthy in Lolo, Florence and Missoula. Arlee is also dealing with being down-drainage of an active fire (the Liberty Fire), and is also seeing Unhealthy air quality this morning.

When air quality is Unhealthy, people with heart or lung disease, smokers, children and the elderly should limit heavy or prolonged exertion and limit time spent outdoors. People with asthma should follow their asthma management plan. People experiencing symptoms of heart or lung disease associated with smoke exposure should contact their health care provider.

Conditions are still somehow Unhealthy for Sensitive Groups in Frenchtown. I was pretty sure it was going to edge up to Unhealthy by 9 a.m., but so far it's holding steady at the lower category. There is still plenty of smoke in the Frenchtown area, it just isn't quite as oppressive at what we're seeing in other parts of the county. Air quality is also Unhealthy for Sensitive Groups in Rock Creek.

When air quality is Unhealthy for Sensitive Groups, people with heart or lung disease, children and the elderly should limit prolonged outdoor exertion.

Air quality is, once again, Hazardous in Seeley Lake. This makes nine Hazardous air quality mornings in the past 11 days for Seeley Lake. And here's the thing - it's not just Hazardous. The levels we're seeing are well beyond the cutoff for Hazardous. We don't actually have a category for the level of particulates we're seeing trapped in the Seeley Lake valley. Air quality for the 1-hour PM2.5 NowCast is considered Hazardous at 250 ug/m3. At 9:00 a.m., NowCast was 600 ug/m3. Yesterday, the NowCast was over 800 ug/m3.

The Health Department has recommended Seeley Lake residents get out of the smoke if they are able to. You can find the official recommendation and some helpful resources online. Please note that the Red Cross Shelter in the Potomac Valley is on stand-by and can be ready to go with an hour's notice. Anyone seeking to stay at the shelter may call the Red Cross of Montana at 1-800-272-6668.

When air quality is Hazardous, all people should limit or avoid outdoor exertion and leave the area or stay indoors with filtered air when possible. Anyone experiencing symptoms of heart of lung disease associated with smoke exposure should contact their health care provider.

The Rice Ridge Fire and Canadian smoke are also impacting air quality in the Swan Valley, where conditions may be Unhealthy or worse. It's going to be a smoky day, folks. There will be some natural convective lift by this afternoon, and the heaviest smoke from nearby fires should move up and out of the valleys, but any clearing will be hindered by surface high pressure that acts like a lid over the area. I don't expect to see any dramatic improvements in most of Missoula County. Seeley Lake should still see a rapid decrease in particulate concentration by noon, but they are unlikely to see clean(ish) afternoon air. The Canadian smoke is relentless and will continue to be pulled into our breathing space throughout the afternoon.

In case you haven't already noticed, wildfire smoke is quirky, and is heavily influenced by topography. The smoke in Seeley Lake is the worst we've ever seen, but it's generally confined to the Seeley Lake valley. For several hours this morning, Clearwater Junction, just 14 miles south of Seeley Lake, had the best air in the county - a relatively pleasant Moderate, with PM2.5 concentrations in the 20s. Unfortunately, the air quality at Clearwater has started to deteriorate, possibly due to smoke that's slowly made it's way out of the Seeley Lake valley and moved downstream to Highway 200. And of course, there's no escaping the Canadian smoke invasion. Clearwater Junction, like the rest of us, will be coping with more Canadian smoke this afternoon.

We will start to see some northwest breezes this afternoon, but they will unlikely be sufficient to create any significant improvements in the air quality. Looking toward the weekend, we may see strong enough winds to scour smoke from the valleys. However, the wind will be largely from the west, which means our old stale Canadian smoke might just end up being replaced with the newer version fresh off the Sunrise fire. Buy local, breathe local?

Anyway.

The strong winds in the next several days may lead to increased fire activity, and increased smoke headed our way. We are entering into a more typical weather pattern for this time of year, and it's the type of weather that we're accustomed to seeing during wildfire seasons - strong afternoon winds, thunderstorms and not much rain. The season is still young. It feels like we've been in smoke forever, but there may be several more weeks of this ahead."

Copyright 2017 Montana Public Radio. To see more, visit Montana Public Radio.