FORECAST SUMMARY: Monday, November 6, 2023, through Thursday, November 9, 2023
Ozone: Ozone season is now over and will start forecasting again in the spring of 2024.
PM-2.5: 24-hour average Fine Particulate levels will range mostly Good, with some Moderates mostly in southern locations Monday and/or Wednesday.
FORECAST DISCUSSION:
This past weekend, some smoke made its way into the southern portion of the state, mostly due to seasonal fire activity in the central U.S. While not nearly as bad as this past summer, the smoke did aid in increasing PM2.5 concentrations on Saturday and Sunday. Daily averages Saturday remained Moderate; however, a couple monitors in the southeast recorded daily averages in the low USG category Sunday. Increased hourly readings remain at a few southeast monitors Monday morning, but the plume is expected to move out during the day. Hourly concentrations of PM2.5 may reach USG at a few southeast sites Monday; however, readings should improve during the day, with mostly Moderate daily averages expected.
On-and-off storm systems are forecast this week. The first is a low-pressure area over Lake Superior on Monday, tracking east into Tuesday. Associated precipitation ends late Monday as the system pulls east, and northerly winds develop as high pressure sinks in from the north. Quiet conditions will be short-lived as the next storm moves in from the west late Tuesday into Wednesday. A wet midweek gives way to dryer conditions for the end of the week.
Northerly winds developing later Monday into Tuesday allow for mostly Good air quality on Tuesday. Winds change to a southerly direction on Wednesday ahead of the approaching weather system. There are some seasonal fires and wildfires ongoing south of Michigan across the east and southeast U.S. It’s uncertain if any associated plumes will track north into our area; however, this is something we will keep an eye on, updating this forecast if necessary. On Thursday, winds switch back to the north, so any increase in PM2.5 Wednesday should not linger. We are forecasting Moderate PM2.5 for Wednesday to account for smoke potential, but any increase should improve towards the Good range Thursday into Friday under northerly winds.
EXTENDED FORECAST:
Extended models show dry, cool conditions as we move into the coming weekend. Northerly winds during this period should keep PM2.5 mostly Good.
Next Forecast Update: Thursday, November 9, 2023