Air quality is expected to reach the orange AQI category in central and northern Minn., which is unhealthy for sensitive groups.
The Minnesota Pollution Control Agency (MPCA) has issued an air quality alert for central and northern Minn. The alert takes effect at 4 p.m. on Saturday, July 22, and runs until 6 p.m. on Monday, July 24. The affected area includes Brainerd, Alexandria, Hinckley, St. Cloud, Bemidji, International Falls, Two Harbors, Hibbing, Ely, Duluth, Roseau, and the tribal nations of Mille Lacs, Leech Lake, Red Lake, Grand Portage, and Fond du Lac.
A narrow band of heavy smoke located across southern Manitoba will be transported towards Minn. by northwest winds. This smoke originated from wildfires in northern Alberta and British Columbia. Ground-level smoke will reach northern Minn. by 4 p.m. on Saturday, behind a cold front. Fine particle levels will reach the orange (Unhealthy for Sensitive Groups) category across north central Minn. by late afternoon Saturday and will persist through the overnight.
On Sunday, as the smoke band continues to move across northern Minn. additional smoke will reach the ground across northeast and central Minn. As daytime heating increases surface temperatures and mixes the atmosphere, elevated smoke will reach the ground around midday. Fine particle levels will be in the orange category across northern and central Minn. on Sunday. Winds will become westerly on Monday. The area of ground-level smoke will begin to move east and exit the state. Air quality should improve by Monday morning across central and north central Minn. However, air quality is expected to remain in the orange category across northeast Minn. on Monday.
Fine particle levels are expected to reach the orange air quality index (AQI) category, a level considered unhealthy for sensitive groups, across central and northern Minn. In the orange area, sensitive groups should limit prolonged or heavy exertion and time spent outdoors.