09/09/2019 Forecast Update


Monday, September 9th, 2019 through Friday, September 13th, 2019

Ozone: 8-hour Ozone concentrations will be mostly Good, but Moderates are a possibility across the south.

PM-2.5: 24-hour Fine Particulate concentrations will range between Good and low Moderate.


Cloudy, cool conditions Monday will be replaced with warm summer-like temperatures starting Tuesday, especially in southern and central portions of the state. The weather change occurs as a low tracks west to east just north of Lake Superior pulling warm front north late Monday into Tuesday. This boundary then sinks back south becoming positioned somewhere across lower Michigan through Thursday. A stronger cold front passing Friday will bring back cooler conditions.

As for air quality, temperatures at the surface and upper levels will increase Tuesday through Thursday as winds turn to a more ozone conducive direction, from the southwest/west. However, at least some clouds and chances for precipitation exist each day. Also, considering the lower sun angle this time of year increased ozone is harder to attain. There is enough concern for Moderate levels across the south that  Moderate will be forecasted in those areas. Any Moderate readings will improve to Good Friday as a cold front brings in a cooler, cleaner air mass.

With a boundary positioned nearby, fine particulate may increase over the next few days. Levels are expected to range from upper Good to low Moderate until Friday when readings return to Good statewide.


Extended models show high pressure moving in for the end of the week and another warm-up looks possible early next week. While the chances for USG ozone are not high, we will evaluate weather conditions Friday to better detail expected air quality levels for the weekend into early next week.

Next forecast update: Friday, September 13th, 2019