FORECAST SUMMARY:
Sunday, July 5th, 2020 through Monday, July 6th, 2020
OZONE: 8-hour average Ozone concentrations will be Moderate with a good chance of USG along the southern tier counties of Lake Michigan.
PM-2.5: 24-hour average Fine Particulate concentrations will range from upper Good to upper Moderate.
AN ACTION DAY ADVISORY IS ISSUED FOR SUNDAY JULY 5th AND MONDAY JULY 6th FOR THE FOLLOWING WEST MICHIGAN COUNTIES:
ALLEGAN... BERRIEN… CASS… KENT... MUSKEGON... OTTAWA… AND VAN BUREN
Weather conditions remain unchanged as we continue with the weekend regarding hot temperatures and increased humidity levels. Forecast models are showing the persistent high-pressure area moving overhead, then the east on Sunday. Although still not that strong, winds will change to a more southwesterly direction. Seeing that many monitors in Indiana, Illinois, and southern Wisconsin have reached USG for ozone late last week, we feel action day advisories are warranted with the wind flow now coming from a southerly direction. Favorable winds will also continue in the southeast and without an air mass change, advisories seem wise there, as well.
The long-range computer forecast keeps us in the same hot, humid air mass until the end of next week so we expect more advisories may be forthcoming. As such, these forecasts will continue to be updated daily.
Fine particulate has also been on the increase, likely due to localized fireworks. Hourly concentrations Sunday morning were up into the USG range. With light winds, fine particulate will be slow to improve, therefore, 24-hour concentrations Sunday will be upper Moderate in many locations, with Moderates lingering into Monday.
EXTENDED FORECAST:
Air Quality will stay mostly Moderate with USG in the most susceptible areas.
Forecast updated by: Stephanie M. Hengesbach; July 5, 2020
Next forecast update: Monday, July 6th, 2020