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Winter Air Quality Update & Forecast
Friday, January 23, 2015 11:17 AM

Locations and Air Quality Conditions


Current Situation Forecast
Air quality impacts are persisting in northwest Montana and down through the Hamilton area this morning. 24 hour average concentrations are UNHEALTHY in Seeley Lake, UNHEALTHY FOR SENSITIVE GROUPS in Libby and Missoula, and MODERATE in Frenchtown, Flathead Valley, and Hamilton. Concentrations in Butte and Helena have been low this morning. Air quality impacts are likely to persist today in northwest Montana and the Missoula area. Beginning tonight, a disturbance will be entering northwest Montana and moving to the southeast across the state. The increased winds and unsettled weather should clear most, if not all, inversions by mid-day Saturday. A strong ridge of high pressure will move over Montana beginning Sunday. This ridge has the potential to create very strong valley inversions and significant air quality impacts. However, the air mass will be comprised of unseasonably warm air. This warm air may reach down the surface in some valleys, clearing inversions and mitigating most air quality impacts. The best chance of this is in southwest Montana, including Hamilton and Butte. This ridge is expected to impact the state through at least mid-week.

Expect air quality impacts in northwest Montana and the Missoula area to range from MODERATE to UNHEALTHY today before improving overnight or tomorrow morning. Air quality on Saturday should be good in most locations due to increased winds and unsettled weather. Beginning Sunday afternoon, air quality impacts are expected for some valleys, especially in northwest Montana. These impacts could reach UNHEALTHY levels. It is possible that the warm air will break inversions in the valleys in southwest Montana. Air quality impacts in those valleys will likely range from GOOD to MODERATE.

Kristen Martin
State Air Quality Meteorologist
Air Resource Management Bureau
Montana Department of Environmental Quality
Phone: (406) 444-0283
Email: kmartin@mt.gov




Low clouds over Flathead Lake this morning, as stable air is keeping pollution trapped near the surface. 

Low clouds over Flathead Lake this morning, as stable air is keeping pollution trapped near the surface.
Source: Polson RV Resort

 
Low clouds over many valleys in northwest Montana this morning.

Low clouds over many valleys in northwest Montana this morning.
Source: NWS

Ventilation is expected to remain poor in western Montana today, but improve on Sunday.

Ventilation is expected to remain poor in western Montana today, but improve on Sunday.

Source: University of Washington 

Unsettled weather will be moving in from the northwest later today.

Unsettled weather will be moving in from the northwest later today.
Source: NOAA

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

Today's particulate report below compares particulate levels received from DEQ's
reporting stations with MDEQ’s wildfire health advisory levels.

Locations and severity of PM 2.5 particulate values since midnight of the date above.
Health Effects Categories City
  Hazardous  
  Very Unhealthy  
  Unhealthy  Seeley Lake
  Unhealthy for Sensitive Groups  Libby
Missoula
  Moderate

 Flathead Valley
Frenchtown
Hamilton
 

  Good

 All other reporting sites. 

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