FORECAST SUMMARY:
Monday, May 24th, 2021 through Friday, May 28th, 2021
Ozone: 8-hour average Ozone concentrations are expected to be Good to Moderate early in the week, then mostly Good.
PM-2.5: 24-hour average Fine Particulate concentrations are also expected to be mostly Good to Moderate early in the week, then mostly Good.
FORECAST DISCUSSION
A cold front, which settled through the state Sunday night, is just south of the Michigan/Indiana border at the time of this Monday morning forecast. It is expected to reverse course and head back north as a warm front through the day Monday and into Tuesday. The area around this front will produce clouds and scattered showers which will reduce any threat of ozone. We can, however, still expect Moderate levels of fine particulates in the southern tier counties.
Tuesday will have the best chance of higher ozone concentrations along the Lake Michigan shore counties. Southwest winds will transport pollutants across the lake with warm temperatures and ample humidity. However, the potential of sustained, ample sunlight will be scattered and concentrations of higher ozone will follow suite. With the high probability of broken to overcast cloud cover, I do not see the potential for any widespread areas of USG level ozone.
A stronger cold front should travel across the state early Wednesday and clean out the current air mass. The remainder of the forecast period should see wind patterns ranging from northerly to easterly as another low-pressure system slowly tracks to the south of us.
As such, I expect the period of Wednesday through the weekend to yield mostly Good Air Quality. At worst, we could see some Moderate conditions west of Detroit as those easterly winds kick in.
As of now, it looks safe to extend the forecast through the holiday weekend. But considering this is the time of year where ozone activity amps up, I will update this forecast on Friday to get us through the long weekend.