FORECAST SUMMARY: Saturday, May 31, 2025 - Sunday, June 1, 2025
Ozone: 8-hour ozone concentrations are expected to range between Good (Green AQI) and Moderate (Yellow AQI).
PM-2.5: 24-hour daily average Fine Particulate concentrations will also range between Good and Moderate.
FORECAST DISCUSSION:
As expected, we saw increases in fine particulate from north to south Friday through early Saturday as a cold front pushed a smoke plume through the state. Several locations experienced hourly increases of fine particulate into the Unhealthy for Sensitive Groups (USG, Orange AQI) range for a few hours, but by mid-morning Saturday, levels had improved, with all areas in the Good to low Moderate range.
High pressure well north of the state will control conditions Saturday and Sunday. Cool northerly winds in place on Saturday keep temperatures mainly in the 60s, and readings only improve a few degrees on Sunday. During the next two days, upper-level winds are from a northerly direction. Smoke models show smoke lingering over the state this weekend, but at upper levels. With not much surface influence, fine particulate and ozone levels are not expected to reach higher than Moderate the next two days.
To our west, thick smoke plumes are sinking into the Dakotas and Minnesota this weekend. By Monday, a ridge will build into our region, and as this happens, smoke will be transported back into the state on a southwest flow. The smoke is expected to move into the western portion of the Upper Peninsula early Monday, then across the rest of the state later Monday into Tuesday. This is something we are watching, and it is possible that an Air Quality Advisory or Alert may be needed for Monday. This forecast will be updated Sunday morning to detail the most recent models and our decision on whether a pollution day is warranted.
EXTENDED FORECAST:
Extended models show a boundary approaching northern areas on Tuesday, bringing precipitation back into the forecast. Warm temperatures and southerly winds ahead of this boundary will keep the threat for increased pollution in place.
Next Forecast update: Sunday, June 1, 2025