How Ozone Action Days are Forecasted

The Michigan Department of Environmental Quality (MDEQ) coordinates with the states of Illinois, Indiana, and Wisconsin to prepare Ozone Action day forecasts. During the Ozone Action season, which runs from May 1st through September 30th, meteorologists from each state work together through a conference call to develop a regional ozone forecast. In order to have an Ozone Action day called in Michigan, the forecast must predict ozone level above 85 ppb over an eight-hour period.

Forecasting Schedule

8:00-11:30 a.m. EDT: Meteorologists from each state individually prepare both a detailed forecast for the next day and a general extended forecast.
11:30 a.m. EDT: The meteorologists and the Lake Air Directors Consortium (LADCo) convene a conference call and discuss the forecasts. A consensus is then reached regarding the outlook for elevated ozone levels for the next day. If weather conditions are not conducive for the formation of elevated ozone levels for the extended forecasts, the participants then determine when the next conference call will take place.
By 1:00 p.m. EDT: The MDEQ meteorologists write a brief meteorological summary stating whether or not elevated ozone levels are expected and whether or not the following day has been designated as an Ozone Action day. The meteorological summary is then e-mailed to a primary contact person at the Grand Valley Metro Council, the West Michigan Shoreline Regional Development Commission, and the Macatawa Area Coordinating Council. These organizations coordinate the Ozone Action programs for Kent, Muskegon, Ottawa, and Kalamazoo counties.

Additional Information

The West Michigan Clean Air Coalition is a partnership of businesses, academic institutions, government agencies, industry, and non-profit organizations in Kent, Ottawa, Muskegon, and Kalamazoo counties working together to achieve cleaner air in the region through the education and promotion of voluntary emission reduction activities.