Air quality alert for NW Minnesota until 10 a.m. Thursday

Wildfire smoke from the western United States and parts of Canada continue to waft out plumes over Minnesota. Most of the smoke is aloft but a stalled cold front over northwestern Minnesota has pushed smoke down to ground level where we breathe.

Air quality has been in the unhealthy range across northwestern Minnesota all day Wednesday.

An air quality alert continues until 10 a.m. Thursday for northwestern Minnesota:

The Minnesota Pollution Control Agency (MPCA) has issued an air quality alert for north central, northwest, central, and west central Minnesota. The alert took effect 9:30 p.m. on Tuesday, Sept. 10, and runs until 10 a.m. on Thursday, Sept. 12. The affected area includes Bemidji, East Grand Forks, Moorhead, Roseau, and the tribal nations of Leech Lake and Red Lake.

Smoke from numerous wildfires across the Saskatchewan province in Canada pushed into northwestern Minnesota overnight Tuesday behind a cold front. The cold front will stall over northwest Minnesota during Wednesday which will cause the smoke to linger through the day Wednesday and into Thursday morning. Air quality is expected to reach the Orange (Unhealthy for Sensitive Groups) AQI category across the alert area during this time. Air quality should improve by Thursday morning as easterly winds blow the smoke westward out of Minnesota.

Fine particle levels are expected to reach the orange air quality index (AQI) category, a level considered unhealthy for sensitive groups, across north central, northwest, central, and west central Minnesota. In the orange area, sensitive groups should limit prolonged or heavy exertion and time spent outdoors.

Improving forecast

Air quality will improve the next few days across northwestern Minnesota as more favorable winds and weather conditions mix smoke. Here’s the forecast discussion from the MPCA:

Updated Wed, Sep 11, 2024

Smoke from numerous wildfires across the Saskatchewan province in Canada has pushed into northwestern Minnesota overnight behind a cold front. The cold front will stall over northwest Minnesota during Wednesday which will cause the smoke to linger through the day Wednesday and into Thursday morning.

Air quality is currently Orange (Unhealthy for Sensitive Groups) AQI category across the alert area, with local (but shrinking) pockets of Red (Unhealthy) air quality. Air quality will continue to gradually improve, and by later this afternoon any local areas of Red should improve to Orange. Significant alert-level smoke should exit west by Thursday morning as easterly winds blow the smoke westward out of Minnesota.

For the rest of Minnesota, the smoke will remain mainly aloft and AQIs are expected to top out at Yellow (Moderate) adjacent to the alert area and upper Green (Good) to low Yellow farther south and east. The smoke incursion should be brief as winds will quickly shift to the south and southeast for Thursday. Particulate is mainly low-end Yellow to our south, and southerly flow will transport this air into Minnesota over the next few days. AQIs will be Yellow Thursday and Friday. For ozone, the summer-like temperatures may allow ozone to reach Yellow on Thursday and Friday.

September summer continues

The air mass over Minnesota is more typical of early August than mid-September. Highs Thursday will push well into the 80s across much of Minnesota.

Highs will remain in the 80s for the next several days, and likely above normal through the end of September.