Air Quality Update For Western Montana, August 8, 2017

Aug 8, 2017

Missoula City-County Air Quality Specialist Sarah Coefield brings us another of her excellent daily reports:

"Good morning, We're seeing smoke impacts in communities near active fires this morning. While most of Missoula County has generally Moderate air quality this morning, thicker smoke is trapped in the Arlee, Lolo and Seeley Lake valleys.

Seeley Lake continues to see the most significant smoke impacts. Air quality is currently Hazardous in Seeley Lake. When air quality is Hazardous, all people should limit or avoid outdoor exertion and stay indoors when possible. Anyone experiencing symptoms of heart of lung disease associated with smoke exposure should contact their health care provider.

Conditions in Seeley Lake will once again rapidly improve when the inversion breaks and smoke from the Rice Ridge Fire is able to lift off the valley floor. The inversion may not fully break until after 12 p.m., but there should be some general, steady improvement throughout the morning hours.

Air quality is currently Unhealthy in Arlee and Lolo. 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.

The Liberty Fire has been slowing down, but it continues to cause morning smoke impacts in Arlee. Conditions in the Arlee area should improve as temperatures warm up and the smoke is able to lift off the ground. The easterly surface and transport winds, coupled with some active fire behavior on the Liberty and Rice Ridge fires, mean folks in the Arlee area may see some additional smoke headed their way this afternoon.

Smoke from the Lolo Peak and Little Hogback fires are impacting Lolo's air quality this morning. These fires were both actively burning overnight, and the smoke became trapped in drainages that empty into the Lolo area. Lolo should see improved air quality by this afternoon when the inversion breaks. Lolo should also benefit from some northerly winds later today that will help push smoke out of the valley.

As for the rest of us, we're primarily looking at visibility impacts this morning. Some atmospheric mixing should kick in by 2 p.m. (which is good and bad - good, because local smoke will lift up and leave us alone for a bit, and bad because all that Canadian haze that's currently far overhead may be pulled down to our breathing space.) While there is a fair amount of smoke overhead, I don't expect conditions in Missoula or Frenchtown to deteriorate beyond some additional haze this afternoon.

It should be noted that the unstable atmosphere may lead to increased fire activity this afternoon, which means more smoke in the pipeline. We're still seeing easterly and northeasterly surface and transport winds in the forecast, so our locally generated plumes and corresponding smoke impacts are likely to follow similar patterns to what we've been seeing for the past several days - smoke from the Sunrise and Lolo Peak fires will likely head off toward Idaho, but smoke from the Liberty and Little Hogback fires may cause impacts in Arlee and Lolo. The Rice Ridge smoke has generally been lingering over the Bob Marshall Wilderness during the day. Today's breezes are a bit more northerly than what we've been seeing though, so it's possible some of the Rice Ridge smoke will impact Seeley Lake in the late afternoon and early evening.

There is a slight chance of isolated dry and wet thunderstorms in the region this evening. That could lead to gusty winds over fires and potential new starts from lightning strikes. This type of more active weather pattern will stay with us for at least the next several days, so there may be additional smoke impacts in our future.

Also, as a heads up, Washington has started to see some more fire activity. The Diamond Creek fire has been growing pretty rapidly. I don't expect to see significant smoke impacts from Washington fires quite yet, but they are also seeing thunderstorm threats in the afternoons, and have similarly dry conditions. We may yet see Washington give Canada a run for its money vis-a-vis tormenting western Montana with long distance smoke.