FORECAST SUMMARY: Monday, July 31, 2023, through Tuesday, August 1, 2023 

OZONE:  8-hour average ozone concentrations are expected to be Good to Moderate.

PM-2.5:  24-hour average Fine Particulate concentrations are expected to be Good to Moderate.

 FORECAST DISCUSSION

Last week we saw a multitude of Action Days, first for smoke and then for ozone.  While this week should be less eventful than last week, we are not completely out of the woods. 

We are currently following a plume of Canadian wildfire smoke dropping down from the central and western Canadian providences.  At the moment, that smoke is staying aloft and not causing any problems other than graying skies.  Northern Minnesota is experiencing some mixing down to the surface and the question is whether or not Michigan can expect any elevated surface concentrations.  The models are not in good agreement on the magnitude, but there is some agreement that some will mix down late Tuesday and into Wednesday.  While I am not currently anticipating levels reaching USG, I would not be surprised to see high Moderate levels during that time period.  Fortunately, this will be a short episode as that smoke should get pushed out, late Wednesday.

Then we shift our focus back to ozone.  While we are starting out the week in the Good range, all indications are that ozone concentrations will begin to creep upwards on Tuesday.  The models are indicating a fairly decent buildup Tuesday into Wednesday, but is keeping the worst of it on the Illinois and Wisconsin side of the lake.  Winds shift to a more southwesterly direction on Thursday and with increasing temperatures and humidly, it could present a problem for Michigan.

 With the uncertainly of the surface level smoke and threat of increased ozone production, I will update this forecast on Tuesday.

EXTENDED FORECAST:

Air Quality should be generally Moderate for most of the middle of the week with some potential for elevated pollutant levels.

Forecast updated by Jim Haywood: Monday, July 31, 2023

Next forecast update Tuesday, August 1, 2023