FORECAST SUMMARY:
Friday, June 19th, 2020 through Saturday, June 20th, 2020
OZONE: 8-Hour average Ozone concentrations will be mostly Moderate and USG Friday and Saturday; Air Quality Air Advisories are in place for both days.PM-2.5: 24-hour average Fine Particulate concentrations will be mostly Moderate through the weekend.
AN ACTION DAY ADVISORY IS IN EFFECT FOR FRIDAY AND SATURDAY FOR THE FOLLOWING MICHIGAN COUNTIES...
IN WEST MICHIGAN:
ALLEGAN... BENZIE… BERRIEN… CASS… GRAND TRAVERSE... KALAMAZOO… KENT... LEELANAU… MANISTEE… MUSKEGON… OCEANA… OTTAWA… MASON… ST. JOSEPH… AND VAN BUREN
IN SOUTHEAST MICHIGAN:
GENESEE… LAPEER… LIVINGSTON… MACOMB… MONROE… OAKLAND… ST. CLAIR… WASHTENAW… AND WAYNE
FORECAST DISCUSSION:
Moderates and USG levels were again seen Thursday and higher readings are expected to continue into the weekend. Michigan remains under the same air mass this weekend and both temperatures and humidity will increase. Considering weather conditions remain conducive for ozone development as we go into the weekend, we are extending the Air Quality Action Day Advisory currently in place to also cover Saturday.
By Saturday, a frontal boundary will be approaching from the west. Southwesterly winds aid to increase temperature and humidity. One factor against increasing ozone may be a bit more clouds over the area. USG ozone concentrations may not be as widespread Saturday, however, there is still enough threat for USG to keep the Action Day Advisory in place.
Models seem to be slowing precipitation changes for later Saturday into Sunday and the boundary coming through will do little to give us a clean out after it passes. With the uncertainty in the current models, we will be evaluating forecast maps tomorrow morning to determine with better certainty that pollution levels will improve Sunday.
EXTENDED FORECAST:
Air Quality should remain Moderate to USG going into the weekend.