FORECAST SUMMARY: Sunday, September 3, 2023, through Monday, September 4, 2023

Ozone: 8-hour average Ozone concentrations are forecast to range between Good and Moderate; with isolated USG possible.

PM-2.5: 24-hour average Fine Particulate levels are expected to be in the Good to Moderate range.

FORECAST DISCUSSION: Sunday features more sunshine than Saturday and temperatures start increasing as ridging builds in from the west. Dry conditions are expected, and gusty southerly winds develop over the region bringing in warmer, muggier conditions. This weather trend is forecast through the Labor Day holiday with highs in the 90s across much of the state.

While sunshine and warmer temperatures the next few days lead towards ozone conducive conditions, stronger winds look to hamper significant pollution development. Forecast ozone models show isolated USG levels along the west Michigan lakeshore due to influence from the lake, otherwise, concentrations remain Moderate. Based on weather maps and pollution trends, we agree with this evaluation. Isolated locations may reach USG, but mostly Moderate ozone is expected Sunday and Monday across the state. We will keep an eye on levels and if this changes, we will update the necessary area(s) to USG, triggering EnviroFlash notifications.

Regarding PM2.5, smoke models show any plumes staying north and west of the region over the next few days. Hourly concentrations across southern areas were ranging low Moderate Sunday morning. Increased wind speeds should keep readings from climbing much the next few days. Daily average PM2.5 concentrations should remain upper Good to low Moderate.

EXTENDED FORECAST: Extended models show a pattern change mid-week with chances for precipitation and cooler conditions. This will improve any pollution increases seen earlier in the week.

Next Forecast Update: Monday, September 4, 2023