Raging Canadian wildfires trigger air quality warnings across upper Midwest

John Yang:

Good evening. I'm John Yang. Poor air quality warnings have been posted in the upper Midwest advising people with heart or lung disease, older adults and pregnant people to limit outdoor activities. The reason is wildfires burning in western Canada, some of them hundreds of miles away.

Meteorologists say that this weekend the smoke and the fine particulate matter it carries could reach Oklahoma, Tennessee and Arkansas. Chris Foltz is a National Weather Service Central Region fire weather program manager.

Chris Foltz, National Weather Service:

The smoke is being lofted into the air and with the weather pattern that's in place right now, we've got an area of low pressure basically just east of Hudson Bay over the Great Lakes, which is bringing that air south.

We also have a ridge of high pressure over the Western U.S. which is kind of helping to funnel that smoke from Canada down through the northern plains and into the middle Mississippi Valley.

John Yang:

Earlier I spoke with Matthew Cappucci, meteorologist at MyRadar. I asked him about the health risks from the smoke.

Matthew Cappucci, Senior Meteorologist, MyRadar:

Well, there are two things I think folks are most likely noticing. Number one, anytime you have this fine particulate matter, we call it PM 2.5 down at ground level, that's dangerous for elderly vulnerable populations. That's a big concern over parts of the upper Midwest, obviously Canada, where the wildfires are originating, but across North Dakota, across much of Minnesota, the entire state of Minnesota under an air quality alert right now, which will likely be pushed into early next week, parts of Michigan north of Chicago and in Wisconsin, a lot of folks of the upper Midwest and Great Lakes.

Now, when the smoke is up high, causing changes to the light, it's harmless. But down near the surface, when we're breathing it in, it's really bad. It's like if you were sitting next to a campfire and breathing that in, you wouldn't want to do that. If I were in North Dakota right now, I'd be turning off my air conditioning and only circulating the air inside my home.

John Yang:

So the danger and the threat is the same hundreds of miles away as if you were sitting next to that fire.

Matthew Cappucci:

Yeah, most definitely. Unless we're really ventilating the atmosphere, taking what's down low and sort of diffusing it higher aloft, then we still have those high concentrations at the surface. We're seeing over 200 on the air quality scale. Anything over 50 is bad, but over 200 in parts of North Dakota right now.

And my fear is that as these fires continue to burn, we're just adding more smoke to the atmosphere and it can surf these jet stream winds in the upper atmosphere down over North America. You know, back in 2023, we saw the smoke reach all the way down to New York City, turning the skies orange as far south as like Tennessee Valley. I don't think, at least initially, it will get that bad farther south, but still over the northern tier, we could see some very high end impacts with this.

John Yang:

And talk a little bit about the air quality index. What does it take to trigger an advisory?

Matthew Cappucci:

It all has to do with the concentrations of how much of that particulate matter is in the atmosphere. The denser the concentrations, the higher the number goes. Anytime I'm seeing numbers around 200, that's the point where you can smell and you can taste the smoke in the air. Your eyes might start to sting, your throat might hurt a little bit. And especially for those vulnerable populations, it's a really significant hazard.

John Yang:

You talked about turning off the air conditioning, that ventilation could bring it into your house.

Matthew Cappucci:

Yeah, anything folks can do to eliminate essentially outside air coming in is what I would really recommend. We hate to say it, but those N95 masks from the COVID era could come in handy because once again, the smoke is made up of these fine little particulates that you don't want to be breathing in. If you have to go outside in the affected areas, that's a really good thing to sort of put one protective layer between you and the air you're breathing in.

John Yang:

And once again, just to remind people, when there's an air quality advisory, are there particular people who need to be especially careful?

Matthew Cappucci:

Anybody with preexisting conditions, the elderly, those with respiratory conditions, underlying conditions, children especially vulnerable to infants, babies, and then sort of after everyone else, middle aged folks too. But, but really, you know, when the air quality gets as bad as it is over parts of the Northern plains in the upper Midwest right now, that's dangerous for anybody.

John Yang:

What are Canadian officials saying about how significant these fires are?

Matthew Cappucci:

They're sort of sounding the alarm, they're sort of peaking their scales right now. For example, Alberta and Ontario are under an extreme risk of wildfires. That's verbiage rarely used by Environment Canada. That's the equivalent up there of the National Weather Service in the U.S. and to sort of max out, the scale says this is a higher end event.

Likewise, the Canadian Interagency Forest Fire center has drawn up a level five out of five. They're basically saying all systems go in terms of combating and fighting these fires. They're allocating all the resources they have to.

When they sort of max out these scales, that's a sign of a really significant event underway. And we're still so early in the summer. We're just getting into June now. This is something we more typically see later into June, into early July. So I do fear this could be another bad fire season for our neighbors to the north.

And one thing we're noting, you know, with climate change, we're seeing sort of a tendency for these heat domes, these blocking bridges of hot, high pressure to last a little longer, be a little stronger, be a little bigger and more stubborn. And that's sort of tilting the scales to higher end fire events.

John Yang:

Matthew Cappucci of MyRadar, thank you very much.

Matthew Cappucci:

Thank you.