FORECAST SUMMARY: Thursday, June 22nd, 2023, through Friday, June 23rd, 2023

OZONE: Ozone concentrations are expected to be in the Moderate to USG range.

PM-2.5: PM-2.5 concentrations are expected to be in the Moderate range

FORECAST DISCUSSION: Yesterday, June 21st, the summer solstice, saw some areas in Michigan reach the USG range for Ozone concentrations. The areas that reached Moderate were not far behind as most monitors were at least in the upper-Moderate range. Today, Thursday, there is a continued Air Quality Alert in place for Ozone for the west and southwestern portions of the state. Continued sunlight and prime Ozone conditions remain in place for those areas as other portions of the state may see increasing cloud cover throughout the day and winds increasing as well. Also, the east and southeastern portions of the state will have upper-level smoke in place from Ontario wildfires, which help blanket the area and block out solar radiation. Upper-level smoke will sometimes cut off Ozone production due to the lack of solar radiation making its way to the surface to complete the Ozone chemical reaction. I am keeping an eye on the upper-level smoke to see if large amounts will mix down to the surface. It appears some will make its way to the surface pushing PM-2.5 concentrations into the USG range but only for isolated hours and should not be a multi-hour event. The overall 24-hour average for PM-2.5 will be in the Moderate range for the majority of the state for today and tomorrow. Due to this smoke and how unpredictable it can be, this forecast will be updated tomorrow, Friday. Also, shifting winds for Saturday may be interesting for Ozone for northern Lake Michigan areas. A few models are showing an Ozone plume around the Traverse City area that stretches into the upper peninsula, so this is another reason this forecast will be updated tomorrow.

EXTENDED FORECAST: Later on Saturday, clouds move in, with Sunday being mostly overcast for the majority of the day. Sunday into Monday presents a Low-pressure system and associated cold front that may bring us some rain as well.

Forecast updated by: Alec Kownacki: Thursday, June 22, 2023

Next Forecast Update: Friday, June 23rd, 2023