* WHAT. The Minnesota Pollution Control Agency has issued an Air Quality Alert for fine particles pollution. The Air Quality Index (AQI) is expected to reach the Red or Unhealthy category. * WHERE. North central Minnesota. * WHEN. From 6 AM CDT to 6 PM CDT Friday. * IMPACTS. Some members of the general public may experience health effects. Sensitive groups, such as people with lung disease (including asthma), heart disease, and children and older adults, may experience health effects. * ADDITIONAL DETAILS. Heavy ground-level smoke from wildfires in central Canada will move into northwest Minnesota early Friday morning behind a cold front. The first band of smoke will quickly move across northern Minnesota during the day Friday and reach northeast Minnesota by the evening. A second round of smoke will reach northwest Minnesota Friday evening. This round of smoke will be more widespread and may impact the northern half of the state on Saturday. The alert may need to be extended to cover the second round of smoke. Cleaner air will move into the state from the west on Sunday and air quality should improve beginning Sunday afternoon.