FORECAST SUMMARY: Thursday, July 21st, 2022, through Friday, July 22nd, 2022

OZONE: 8-hour average Ozone concentrations are expected to range from Good to Moderate.

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

FORECAST DISCUSSION:

A low-pressure area travels from eastern Iowa Thursday to just east of Detroit Friday. Small chances for precipitation due to this system exists overnight Thursday across the south, but most locations will remain dry. For the weekend, an upper level low well north of Lake Superior will cause on and off upper-level systems to pass by with chances for storms; the greatest threat for precipitation looks to be later Saturday into Sunday.

As for air quality, generally west to northwesterly surface and upper-level winds remain through Friday with a good amount of sunshine. Warm temperatures also remain but expected winds are not the typical flow for increased ozone. Levels Thursday and Friday may increase but readings higher than Moderate are generally not expected. There is a chance an isolated monitor could hit low-end USG along the western lakeshore, but we do not feel the threat is enough to warrant an Action Day. By Saturday, weather conditions become a bit more uncertain. A system approaches bringing with it decent chances for precipitation, however, before it arrives, winds shift to the southwest and the question will be cloud cover. If sunny skies remain most of Saturday, increased ozone could be possible. We will do a forecast update tomorrow to get a better handle on expected conditions for Saturday.

Hourly fine particulate in the low Moderate range early Thursday is likely due to a light plume of smoke making its way to the surface. There has been a small increase in fine particulate due to this here in Michigan, but more significant increases have been reported south and west across parts of Illinois and Indiana. The plume was pushing south Thursday with improving conditions. West to northwesterly winds the next couple of days should keep daily concentrations of fine particulate mostly Good to low Moderate.

EXTENDED FORECAST:

A stronger boundary brings decent chances for storms later Saturday into Sunday. With increased clouds, precipitation, and cooler conditions after the boundary passes, elevated air quality conditions are not anticipated early next week.

Forecast updated by: Stephanie Hengesbach: Thursday, July 21st, 2022
Next Forecast update: Friday, July 22nd, 2022