FORECAST SUMMARY:
Saturday, July 4th, 2020 through Sunday, July 5th, 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 be mostly Good to Low Moderate.
AN ACTION DAY ADVISORY IS ISSUED FOR SUNDAY FOR THE FOLLOWING WEST MICHIGAN COUNTIES...
ALLEGAN... BERRIEN… CASS… KENT... MUSKEGON... OTTAWA… AND VAN BUREN
FORECAST DISCUSSION
Despite the hot weather, Air Quality has stayed remarkably good through the week. We have recorded only one USG and that was the East 7-Mile monitor on Thursday. Much of that good fortune can be traced back to favorable winds which switched from southeast to northwest during the course of the week.
Now the models are showing that the high pressure ridge axis will pass over during Sunday and light winds will switch to the southwest. Seeing that many monitors in Indiana, Illinois, and southern Wisconsin hit USG, yesterday, we think it prudent to issue an advisory since winds will now come from that direction.
Long range computer forecast keeps us in the same hot, humid air mass until the end of next week so I expect more advisories may be forthcoming. As such, these forecasts will continue to be updated daily.
EXTENDED FORECAST:
Air Quality will stay mostly Moderate with USG in the most susceptible areas.
Forecast updated by Jim Haywood: Saturday, July 4th, 2020
Next forecast update: Sunday, July 5th, 2020