Last night smoke from the Miller Peak Fire drained into nearby drainages and into Missoula resulting in air quality ranging from Unhealthy for Sensitive Groups to Unhealthy. Smoke from fires west of Missoula in Idaho, Oregon, Washington, and California, is resulting in Moderate to Unhealthy for Sensitive Groups across Missoula County. There is a lot of smoke across western states moving towards Missoula, as seen in the GOES 18 satellite image (there are too many fires to label in the West – check out InciWeb for info on all major fires).
This weekend across Missoula County, calm, swirly winds could result in smoke from fires out west to stick around and will likely result in air quality that is Moderate to Unhealthy for Sensitive Groups. Slightly stronger easterly winds on Sunday may bring in less smoky air and help disperse smoke lingering in the air, which could be hindered if an inversion develops. Check the smoke outlook (blue box around Missoula – click on the !) on the Fire and Smoke Map for weekend updates.
High temperatures are in the forecast for this weekend and with the potential for smoke, it may complicate things. When smoke pools in a valley like Missoula overnight, it takes the sun’s rays longer to warm up the valley floor and heat the near surface air. This prevents the air from rising and mixing with the atmosphere. If surface level air is smoky, the smoke gets trapped creating a prolonged period of degraded air quality. This is what everyone refers to as the inversion (although it’s really a new inversion each time). Wind can break up an inversion by physically mixing the air instead of heating it up. The light easterly winds forecasted for this weekend and high temperatures may worsen the pooling of smoke from the Miller Peak Fire in adjacent drainages, especially those west of the fire, so Lolo and Miller Creek. With the likelihood of an inversion, the smoke can travel further down drainages closer to more populated areas like Missoula. Because winds will be light and will die down in the evening, there is still the chance of smoke draining to the east into Clinton overnight.
Mushu, your local air quali-kitty, keeps up to date on air quality around Montana by reading MT DEQ’s Smoke Outlooks in case she wants to get out of town to cleaner air. If recreating this weekend, check the Fire and Smoke Map and MTfireinfo.org for fire restrictions before heading out to plan accordingly. Smoke takes a toll on everyone, and everyone reacts differently to it. If air quality is Unhealthy for Sensitive Groups to Unhealthy consider recreating inside a facility with filtered air or choosing a less intense activity. For information on cleaning your indoor air and health impacts of smoke, check out Thursday’s air quality update and click your way over to Montanawildfiresmoke.org for more details on DIY air cleaners, HEPA air cleaners, and more!
Kerri Mueller
Air Quality Specialist
Office: 406.258.3642 | Cell: 406.274.7694
301 West Alder, Missoula, MT 59802
MissoulaPublicHealth.org