Wildfire Smoke Update
for
Wednesday, September 12, 2012 2:16 PM

Satellite Photos | Locations and Smoke Conditions

Today's Report and Forecast	Today's Summary
Air quality is starting to moderate and improve across once-smoky regions of the state. Atmospheric winds that are blowing from the northwest are pushing any smoke to the south and southeast. Also, cold overnight temperatures and lighter winds today are keeping fire activity down. The combination of these two factors means that less smoke is being produced today, and the atmosphere is working to get rid of the smoke that has been around since this past weekend. Air quality in Helena, Great Falls, and eastern Montana has returned to GOOD this afternoon and visibility has greatly improved. The heaviest smoke yesterday was in southwestern Montana, from Missoula to Butte to Livingston. Smoke is still in this region today, but air quality impacts are generally less with less smoke. Cumulative smoke concentrations in Butte and Bozeman are still UNHEALTHY FOR SENSITIVE GROUPS, but most hourly concentrations today have been GOOD. Likewise, cumulative smoke concentrations in Missoula and West Yellowstone are MODERATE but hourly concentrations have also been GOOD today. The smokiest spot in the state with the worst air quality is still down the Bitterroot Valley. Hourly particulate concentrations in Hamilton have been UNHEALTHY FOR SENSITIVE GROUPS since early this morning, but cumulative exposures are still VERY UNHEALTHY. Air quality is being heavily impacted by the Sawtooth fire just west of Hamilton. Temperatures will become very cold again tonight and valley inversions will develop again. Hamilton saw a dramatic spike in particulate concentrations overnight as that inversion developed, and similar conditions can be expected tonight. By tomorrow, temperatures will start to warm up as a ridge of high pressure makes its way east over the western US. Atmospheric winds will gradually change direction throughout the day, which will change the direction of any smoke that is produced. By the evening, winds will come mostly from the west, so smoke that has been contained to southwestern Montana today will gradually be ushered to locations north and east of there. The air will become much more stable and stagnant throughout the day and through Friday. Any smoke that is produced will stand a better chance of settling in the valleys and near the ground to adversely affect air quality. Temperatures will be warmest on Saturday ahead of a cold front, which will drop from the northwest late Saturday and through Sunday. Behind the cold front, for the very beginning of the week, atmospheric winds will blow from the northwest again (like they are today). Therefore, we can expect similar air quality conditions on Sunday and Monday as we do today, where most air quality impacts are only across southwestern Montana. Next week could potentially be a very active weather week, where frequent weather systems and cold fronts could help to reduce fire activity and help to bring an end to fire season.	Air quality in Helena, Great Falls, and eastern Montana has returned to GOOD this afternoon and visibility has greatly improved. The heaviest smoke yesterday was in southwestern Montana, from Missoula to Butte to Livingston. Smoke is still in this region today, but air quality impacts are generally less with less smoke. Cumulative smoke concentrations in Butte and Bozeman are still UNHEALTHY FOR SENSITIVE GROUPS, but most hourly concentrations today have been GOOD. Likewise, cumulative smoke concentrations in Missoula and West Yellowstone are MODERATE but hourly concentrations have also been GOOD today. The smokiest spot in the state with the worst air quality is still down the Bitterroot Valley. Hourly particulate concentrations in Hamilton have been UNHEALTHY FOR SENSITIVE GROUPS since early this morning, but cumulative exposures are still VERY UNHEALTHY. Air quality is being heavily impacted by the Sawtooth fire just west of Hamilton.
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

This is the visible satellite image from 1:45 this afternoon. Montana appears to be relatively smoke-free, except for the visible smoke plume from the Sawtooth Fire in the Bitterroot Valley. 




 
Visibility is good in Big Sky today, as details are still discernible on Lone Peak off in the distance.




This morning’s analysis from NOAA’s satellite services division shows the active fires in Montana and the smoke plumes combining and spreading downwind (the analyzed smoke is based on yesterday’s satellite coverage, the fire detects are based on last nights satellite coverage).


Red indicates hot spot detected. Green represents thin smoke, yellow is moderate smoke, and purple is dense smoke. Fire size is exaggerated for visibility at this scale. To identify individual fires on graphic above go here: http://activefiremaps.fs.fed.us/lg_fire2.php 

Smoke conditions have greatly improved in the Helena Valley, as this webcam at the Gates of the Mountains looks south across the valley. Some of the peaks on the horizon are over 40 miles away, and yet they are finally visible again!

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

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.