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Wildfire Smoke Update
for
Friday, September 28, 2012 8:35 AM

Satellite Photos | Locations and Smoke Conditions


Today's Report and Forecast Today's Summary
After a small spike in particulate concentrations yesterday afternoon in Missoula, Frenchtown, the Flathead Valley, and Seeley Lake, air quality improved somewhat overnight. Cumulative smoke exposures are UNHEALTHY FOR SENSITIVE GROUPS, but hourly concentrations are GOOD. Hourly concentrations in Missoula, however, are very close to MODERATE. Cumulative exposures are still UNHEALTHY in Hamilton, but hourly concentrations are UNHEALTHY FOR SENSITIVE GROUPS. In Butte, hourly concentrations are MODERATE to GOOD, but cumulative exposures are UNHEALTHY FOR SENSITIVE GROUPS. Cumulative exposures are MODERATE in Libby, Bozeman, Great Falls, Billings, and Sidney, but all hourly concentrations have been GOOD today. The air monitor in Helena is having some technical difficulties since yesterday evening, so one should use the visibility guidelines until the monitor is working properly. It is important to remember that one should use the visibility guidelines with some caution early in the mornings, as the relative humidity is very high. Moisture and high relative humidity also act to distort visibility.

Wildfire smoke is fully present in the atmosphere over Montana, and especially western Montana. Like yesterday, we can expect a small spike in particulate concentrations this afternoon as the air warms up and the smoke mixes down to the surface. We are still under a stable ridge of high pressure, so smoke will stay around the region and near the ground. Winds will remain mostly light, so smoke will not blow away from the region either. The Bitterroot, Swan, and Missoula Valleys will see the most wildfire smoke this afternoon.

There will be another update this afternoon with the latest smoke conditions and a full forecast.
Please see "Today's Report and Forecast" (left). There will be another update this afternoon with the latest smoke conditions and 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: DEQMTSmoke@mt.gov




 




 








 




Real time particulate information is currently available in most of the larger urban areas from MTDEQ's Today's Air website.

Today's particulate report below compares particulate levels received from DEQ's
reporting stations with MTDEQ’s Health Effect Categories.

Locations and severity of PM 2.5 particulate values over the past 24 hours from the time above.
Health Effects Categories City
  Hazardous  
  Very Unhealthy  
  Unhealthy  Hamilton B24, B8
  Unhealthy for Sensitive Groups  Flathead Valley B24
Seeley Lake B24
Missoula B24
Frenchtown B24
Butte B24, B8
  Moderate

 Dillon B24
Great Falls B24, B8
Billings B24
Sidney B24
Libby B24
Bozeman B24
 

  Good

 West Yellowstone 

B1(x) One-hour BAM value (number of values)
B8(x) Eight-hour average BAM
B24 24 hour  average BAM value
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.