FORECAST SUMMARY: Sunday, July 16, 2023, through Monday, July 17, 2023
OZONE: 8-hour average Ozone concentrations will average mostly Moderate.
PM-2.5: 24-hour average Fine Particulate levels will range from Moderate to Unhealthy for Sensitive Groups (USG).
Air Quality Action Day Advisories have been issued for Sunday, July 16th and Monday, July 17th, 2023
The Action Day Advisory for Sunday, July 16th is a Statewide Alert.
The Action Day Advisory for Monday, July 17th is for the following counties in the central and southern portions of the Lower Peninsula:
Mason, Lake, Osceola, Clare, Gladwin, Arenac, Oceana, Newaygo, Mecosta, Isabella, Midland, Bay, Huron, Muskegon, Montcalm, Gratiot, Saginaw, Tuscola, Sanilac, Ottawa, Kent, Ionia, Clinton, Shiawassee, Genesee, Lapeer, St. Clair, Allegan, Barry, Eaton, Ingham, Livingston, Oakland, Macomb, Van Buren, Kalamazoo, Calhoun, Jackson, Washtenaw, Wayne, Berrien, Cass, St. Joseph, Branch, Hillsdale, Lenawee, and Monroe
FORECAST DISCUSSION:
Smoke forecast models continue to show the smoke plume tracking through the state Sunday into Monday and this plume is clearly seen on satellite imagery Sunday morning. Increases in PM2.5 concentrations have been recorded Sunday morning across the western portion of the state and increases in concentrations will move east and continue through much of today. Air Quality Index (AQI) levels into the Unhealthy for Sensitive Groups range are likely with possible hourly concentrations into the Unhealthy level. The smoke plume pushes south Monday as a boundary moves through. This will improve PM2.5 levels across the northern portion of the state. The plume, however, remains across central and southern locations keeping the threat for increased PM2.5. Because of this, we are extending the Air Quality Action Day into Monday for the counties noted above.
Chances for precipitation Sunday, then cooler surface and upper-level temperatures Monday should keep ozone from increasing the next few days. However, increases in PM2.5 are known to enhance ozone production. We are forecasting Moderate ozone Sunday and Monday, but we will be watching ozone levels and if we feel ozone will increase into the USG range, we will update the necessary forecast areas to reflect the change, triggering EnviroFlash notifications.
EXTENDED FORECAST:
There are signs the smoke plume could clear the region early next week, but lingering fine particulate could keep both PM2.5 and ozone in the Moderate range.
Forecast updated by: Stephanie Hengesbach on Sunday, July 16th, 2023
Next Forecast Update: Monday, July 17th, 2023