FORECAST SUMMARY: Friday, September 29, 2023, through Monday, October 2, 2023

Ozone: 8-hour average Ozone concentrations will range Good to Moderate.

PM-2.5: 24-hour average Fine Particulate levels will range between Good and Moderate.

FORECAST DISCUSSION: A frontal boundary brings precipitation in the forecast Saturday in the Upper Peninsula while high pressure produces dry weather across the rest of the state. Temperatures increase through early next week as warmer air ushers in on a southerly wind. Temperatures for the end of September/early October will be more summer-like than fall-like. Highs climb into the 70s Saturday and approach the 80-degree mark early next week. After the Saturday precipitation up north, the next chance for precipitation across the state should hold off until midweek next week.

As for air quality, both PM2.5 and ozone have been Good the past few days and Good readings should continue Friday. Less cloud cover in the Lower Peninsula and warmer surface and upper-level temperatures on a southerly wind makes weather conditions conducive for ozone starting Saturday, lasting through the period. What hampers ozone development, however, is less solar radiation that makes ozone generation less likely. While we anticipate ozone to increase into the Moderate range across parts of the state, readings into the USG range are not likely.

The current weather scenario does not bring wildfire plumes over the state which would result in increased PM2.5. But weaker winds from the south may allow for increased levels, especially in the southeast portion of the state. PM2.5 concentrations will range from middle Good to middle Moderate.

EXTENDED FORECAST: Warmer/dry conditions lingering early next week keep the chance for Moderate ozone and PM2.5 in the extended forecast.

Next Forecast Update: Monday, October 2, 2023