The recent smoke event in Wisconsin was one of the worst recorded in terms of how poor and widespread the air quality got, at least since record keeping began in the 2000s.
For multiple days in a row, the air quality across the region stayed at the hazardous level.
“This was definitely an impressive event that I think most Wisconsinites will say that they had not experienced before in their lifetime,” said Alex Oser, the air quality meteorologist for the Wisconsin Department of Natural Resources.
Oser says in general the forecasting went as planned, trying to give people as much of a heads up as possible that the smoke was coming and air quality would be dropping.
“One thing we were a little surprised to see was that the AQI [Air Quality Index] values made it up to the hazardous level as quickly as they did. We could tell as the forecast lead time was you know getting closer and closer to the event time, the models were definitely showing that there was going to be a decent amount of smoke at the surface,” said Oser. “We were thinking the very unhealthy level was definitely going to be reached, but a little bit surprised to see the hazardous level reached as quickly as it was.”
Forecasting smoke
Smoke is difficult to forecast more than 24 to 48 hours in advance, which is why the DNR will re-issue advisories as poor air quality continues.
Part of this is because you can’t forecast where a fire is going to start.
“We saw some impacts starting on Tuesday,” said Oser. “On Monday, those trees hadn't even burned yet.”
Air temperatures, humidity, rain, the type of landscape the fires are burning, the wind direction, pressure systems, and our proximity to the fires all need to be factored into forecasting to try and gauge how much smoke the fires will produce and if it will impact our air quality.
The air quality standards are set by the Clean Air Act.
The DNR is issuing advisories based on the short-term, 24-hour standard.
“EPA has defined a concentration of PM 2.5, which is 35.5 micrograms per cubic meter. So, as long as your 24-hour average of PM 2.5 is at or below that value, it's considered satisfactory,” said Oser. “It will be given an AQI value of somewhere between one and 100. That ranges from good or green AQI through moderate or yellow AQI.”
When the air quality goes beyond that moderate level is when the DNR will start issuing advisories.
Why are different air quality apps telling me different things?
When the smoke was impacting air quality, people may have notice different apps or websites giving different air quality readings.
The air quality monitor needs to be detecting PM2.5, some only check for Ozone.
People may also notice that the air quality level doesn’t always necessarily match with what they’re seeing or smelling outside.
That’s likely because many of the maps, like the EPA’s Air Now Fire and Smoke map, only updates once an hour.
“Air quality can actually change pretty drastically,” said Oser. “I saw within a 30-minute time period, we went from like 225 micrograms per cubic meter, like a concentration of PM 2.5, down to 60. That’s a massive drop in like 30 minutes.”
With so many people trying to access the maps last week, some of the websites got bogged down and were slow to load.
Where can I get air quality advisories?
People can get the latest air quality forecasts by visiting the Wisconsin DNR’s air quality website. That’s also where you can view current air quality conditions.
Other good resources include:
- Download the free WisconsinAQM mobile app to receive air quality updates from anywhere using a mobile device. Download in the Apple App Store or the Google Play Store.
- View current wildfire and smoke conditions across North America with the AirNow Fire and Smoke map.
- Sign up to receive air quality advisory notices to your email inbox or via text.
- Sign up to receive customizable EnviroFlash air quality notifications.
Will we see more smoke this summer?
Most of the smoke impacting the region is coming from fires in northern Minnesota and Ontario.
The CBC is reporting that early estimates suggest that this will be Ontario’s worst wildfire season on record.
There are more than 100 fires burning across the province, 49 are not contained.
Cooler temperatures and cloud cover has reduced fire activity in northern Minnesota and Ontario this week, leading to our improving air quality.
“With enough time, with the right conditions, again, hot, dry, and windy conditions, these fires can ramp back up,” said Oser. “It's something that we're definitely keeping an eye on.”
Wildfires are a natural part of the ecosystem. Most of the fires burning right now were caused by lightning.
Human-driven climate change is leading to more frequent hot, dry, and windy conditions that contribute to more wildfires and longer fire seasons.
