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Wildfire Smoke Update
for
Wednesday, September 26, 2012 8:20 AM
Satellite Photos
| Locations and Smoke Conditions
Today's Report and Forecast |
Today's Summary |
The cold front that passed across western Montana overnight got rid of more valley smoke than was expected. Cumulative smoke exposures are still high in most of these valleys, but hourly concentrations have dropped to healthier levels for the time being. Cumulative particulate concentrations in Hamilton are VERY UNHEALTHY, but hourly concentrations have dropped to levels that are UNHEALTHY FOR SENSITIVE GROUPS and UNHEALTHY. In Missoula, Frenchtown, and Butte, cumulative concentrations are UNHEALTHY, but hourly concentrations are GOOD (but very close to MODERATE). Cumulative concentrations in Libby, the Flathead Valley, Seeley Lake, Great Falls, and Helena are UNHEALTHY FOR SENSITIVE GROUPS, but hourly concentrations have also dropped to levels that are GOOD and near MODERATE. The cold front has yet to pass across eastern Montana, so smoke conditions are still MODERATE there. Finally, smoke has continued to stay away from a narrow band along southern Montana, so air quality from Dillon to Bozeman to Billings is GOOD.
If you take a look outside in almost any valley in western Montana, the smoke is still visible in the sky. The mountains are still probably a little hard to see and the sky may have a red-ish tint in the morning. Yes, the air quality has improved this morning, but with smoke still in the area, we are not out of the clear yet. I do not expect air quality to become as poor as it has been for the last few days, but hourly concentrations may become MODERATE in most valleys, and generally UNHEALTHY FOR SENSITIVE GROUPS in the Bitterroot Valley. Eastern Montana will stay MODERATE as the cold front will be very slow to pass there, but the central plains should generally stay GOOD.
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
|
Air quality has improved here in Missoula, but smoke is still in the air over the valley.

Similarly, air quality has improved in the Helena Valley. The North Hills are visible on this webcam on Capitol Hill, but the Sleeping Giant (22 miles away) is not visible.
Red indicates hot spot detected. Grey represents smoke seen by satellite. Fire size is exaggerated for visibility at this scale. To identify individual fires on graphic above go here: https://activefiremaps.fs.fed.us/lg_fire2.php
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 |
Hamilton B24 |
|
Unhealthy |
Frenchtown B24
Missoula B24
Butte B24
-Hourly concentrations have been GOOD- |
|
Unhealthy for Sensitive Groups |
Libby B24
Flathead Valley B24
Seeley Lake B24
Helena B24
Great Falls B24
-Hourly concentrations have been GOOD- |
|
Moderate |
Sidney B24
|
|
Good |
Billings
Bozeman
West Yellowstone
Dillon
|
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.