FORECAST SUMMARY:
FRIDAY, JUNE 18, THROUGH MONDAY, JUNE 21, 2021
OZONE: 8-hour Ozone concentrations are expected to be Good throughout the weekend with possible Moderate levels in place along the Lake Michigan shoreline and Metro Detroit. Into Monday, levels are expected to be Good due to another system making its way into the region.
PM-2.5: 24-hour average Fine Particulate concentrations will be Good to low Moderate over much of the region.
FORECAST DISCUSSION:
After a system made its way through the region Friday morning, subtle clearing is expected to occur for much of the afternoon with a moderate chance of additional storms to develop later Friday afternoon into the evening. Left over rain is expected into Saturday morning as another Mesoscale Convective System is predicted to make its way through central-southern Michigan. With this MCS, WSW winds are expected, which helps to explain the Moderate Ozone levels along the Lake Michigan shoreline.
Into the day on Saturday, a stalled front is expected over mid-Michigan, which will slightly lift off to the north later Saturday night, eventually making its way on a more SE track into Sunday and Monday. The stalled front will result in a Low-pressure system over the MI/IN border and will lift off as the front leaves the area. This front will be responsible for the expected rain on Monday. Overall, Ozone levels are expected to generally be Good with some Moderate levels of Ozone near west/southwest MI. In the southeast, low-Moderate PM2.5 concentrations could occur as well.
EXTENDED FORECAST:
With the frontal passage next Monday, we expect Good Air Quality for the start of the week as the rain showers exit the area. This will give way to a High-pressure system to our south which will present us with relatively clear skies.