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Wildfire Smoke Update
Wednesday, September 4, 2013 9:00 AM

Satellite Photos | Locations and Smoke Conditions

Today's Report and Forecast Today's Summary
We are seeing air quality impacts across parts of western and central Montana this morning. With the cloud-cover over the state last night and this morning, it is almost impossible to tell the exact source of the smoke. However, with high atmospheric winds blowing from the southwest, there are several wildfires in Idaho as well as the Rim fire in California that are upwind of Montana, so these are the most likely sources. Cumulative particulate concentrations, when averaged over the last 24 hours, are UNHEALTHY FOR SENSITIVE GROUPS in Bozeman, Missoula, and Hamilton, but hourly averages have been GOOD since midnight at each location. Similarly, cumulative particulate concentrations are MODERATE in Frenchtown, Seeley Lake, Helena, Butte, Great Falls, and Lewistown, but hourly concentrations have also been GOOD since midnight. Air quality has been consistently GOOD across the northern half of the state and most of eastern Montana.

High atmospheric winds will continue to blow from the southwest throughout the day today as a weak weather disturbance passes through the Northern Rockies. This means that we will continue to get smoke upwind from here—particularly from Idaho and California—but the atmosphere will be more unstable today. Afternoon thunderstorms will develop again with above-average temperatures. We will continue to see hazy skies across much of western and central Montana throughout the day with widespread MODERATE to UNHEALTHY FOR SENSITIVE GROUPS cumulative impacts. Hourly concentrations should stay generally GOOD, but may reach MODERATE levels for a few hours this evening, particularly across southwestern Montana and the Bitterroot Valley. The northern half and most of eastern Montana will continue to see GOOD air quality today.
There will be another update later this afternoon with a full forecast.
Residents near active fires and under plumes aloft need to remain aware of current conditions and use the visibility guidelines to guide their activity decisions as the situation changes.

Air Quality Bureau
Montana Department of Environmental Quality
Phone: (406) 444-3490
Email: DEQ-ARMB-Admin@mt.gov

This is the visible satellite image from 8:15 this morning showing mostly cloudy skies across Montana. 

This is the visible satellite image from 8:15 this morning showing mostly cloudy skies across Montana.

This webcam in Missoula shows the good visibility across the valley this morning.

This webcam in Missoula shows the good visibility across the valley this morning.


The smoke report below compares particulate levels where information is available to MDEQ’s Health Effects Categories. Real time particulate information is currently available in most of the larger urban areas from several different sources including: DEQ run PM-10 BAMS and PM2.5 BAMS, NWS ASOS visibility monitors, and USFS remote access Nephelometers and BAMS. These advisories represent conditions between midnight and 8 AM and may change substantially throughout the day.

Locations and severity of forest fire smoke reports since midnight of the date above at reporting stations.
Health Effects Categories City
  Very Unhealthy  
  Unhealthy for Sensitive Groups  Bozeman B24
Hamilton B24

 Missoula B24, B8
Frenchtown B24, B8
Seeley Lake B24
Helena B24
Butte B24
Great Falls B24
Lewistown B24


Flathead Valley
West Yellowstone

B1(x) One-hour BAM value (number of values)
B8(x) Eight-hour average BAM
B24 24 hour  average BAM value
Vis(x) Visibility value (number of hours)
Vis(am/pm) Visibility value from twice/day reporting stations

Local impacts in areas immediately adjacent to active fires are expected to exceed some or all of the advisory levels.  DEQ recommends the use of local visibility guidelines to evaluate possible health risks and make informed activity decisions.