MINNEAPOLIS (AP) - A new air quality alert has been issued for the southern half of Minnesota.

The Minnesota Pollution Control Agency issued the alert for southern, eastern and parts of central Minnesota effective Friday from noon to 8 p.m. The affected area includes the entire Twin Cities metro area, Marshall, Rochester, St. Cloud and the tribal nation of Upper Sioux.

The air quality index is expected to move into the unhealthy for sensitive groups category Friday due to a combination of unseasonably warm temperatures, mostly sunny skies and high ozone levels.

Conditions are expected to improve around sunset Friday.