FORECAST SUMMARY: Monday October 9th, 2023, through Friday October 13th 2023

Ozone: Ozone concentrations are expected to be in the Good range.

PM-2.5: PM-2.5:  PM-2.5 concentrations are expected to be in the Good range with some hourly low-Moderates.

FORECAST DISCUSSION: Fall has definitely fallen upon us here in Michigan with average surface temperatures remaining in the 50s for the foreseeable future and leaves ever-changing in color. This week also has its fair share of rain in the forecast with essentially every day this week having a chance of rain somewhere throughout the state. These cooler temperatures are solely due to northerly winds which will dominate the weather pattern this week. The main threat of rain this week will be Thursday and through the weekend as a Low-pressure system makes its way toward the Great Lakes from the southwest. Although the Low-pressure itself will stay just to our south, Michigan will still see impacts in the form of rain and some breezy to windy conditions. As of now, these rainy and breezy conditions look to last through the weekend.

In terms of air quality, the Ozone season is slowly but surely winding down with days becoming shorter and temperatures staying cooler. Coupled with the rain this week, Ozone will be in the Good range with rain keeping the airmass clean and cooler temperatures inhibiting the development of Ozone. Last week, we saw PM-2.5 concentrations rise into the USG range for an hour or two mainly in the Detroit and other populated areas. This is typical during early morning commutes with light winds. We usually see those conditions as mornings become cooler and, almost like clockwork, in the wintertime due to surface-level atmospheric inversions trapping air from dispersing. We may see those kinds of concentrations this week, but rain and wind later in the week will help keep PM-2.5 concentrations in the Good range as well.

EXTENDED FORECAST: The weekend continues what the work week ends with: rain and wind. Sunday starts to see the rain lifting off, but northerly winds carry on, with surface temperatures in the 50s. Overall air quality will be Good.

Next Forecast Update: Friday, October 13, 2023