- A rash of Canadian wildfires will likely pump more smoke streams into the United States this summer.
- This is likely to happen after cold fronts pass through the northern tier of the United States
- This means that cold fronts will not bring as much fresh air as we are used to.
Wildfires in Canada will radically change the country's weather this summer, making even the basic passage of a cold front more unusual in one key respect.
A cold front provides summer relief for some. Think of a typical heatwave in June, July, or August. It has been hot and humid for several days. There may be haze in the sky due to ozone, resulting in unhealthy air quality, at least for sensitive groups.
A woman dries off after cooling off in the spray of a fire hydrant during a heat wave on July 1, 2018 in Philadelphia, Pennsylvania.
(Jessica Korkounis/Getty Images)
But there is hope. I noticed that forecast weather maps show a cold front about to sweep through. That beautiful blue line with triangles pointed in your direction is sure to bring rain, and then cold, dry air from Canada.
After the front pass, you can open your windows and let the fresh air in, giving your hard-working air conditioner a break, right?
An example of a summer cold front sweeping away moist (and hot) air.
What's different this summer? Yes, there will still be Canadian cold fronts providing relief from the heat and humidity of the northern United States
But this summer, northerly to northwesterly winds following a cold front may also sweep smoke from hundreds of Canadian wildfires into parts of the United States.
We have seen Several examples of this since early Mayculminating in thick, multi-day smoke over the Northeast and Great Lakes around June 7.
Although it may seem strange to have smoky air behind a cold front, we've seen it happen several other times in recent years, including Last July, July 2021, May 2019, June 2015 And August 2014.
Here's what to expect. This smoke may simply be above ground. In this case, you'll notice hazy white skies during the day, and stunning pink sunsets and sunrises. If you're a stargazer, this smoke can periodically obscure your view of the night sky, if it's dense enough.
Sometimes, that smoke can fall close to the ground, resulting in dangerous air quality, especially if the fire is closer, as was the case in Quebec, and the impact of the Canada fires on the northeastern U.S.
Don't automatically assume that cold temperatures and low humidity are a good idea to open windows and go for a walk or run.
Check the air quality in your area first. If you notice the term “PM2.5” mentioned in your air quality forecast, it means there are smoke particles in the air, the type of particles that can settle deep in your lungs.
If the AQI is orange or higher, it is at least unhealthy for sensitive groups and you should consider delaying exercise or spending extended time outside until the air quality improves.
How long will this scenario continue? In short, until a significant portion of larger wildfires are extinguished.
In theory, this could happen if a persistent wet pattern settled in fire-infested areas. But it is difficult to do this in the summer in Canada, where rainfall often occurs Scattered thunderstorms could spark new firesinstead of large areas of heavy rain.
Furthermore, remote wildfires are raging in Canada They are usually left to burn if they do not affect the property. This is healthy for the ecosystem, but it also means that huge plumes of smoke will continue to come out.
As of the time this article was published, there were more than 400 active fires in Canada, according to the Canadian Interagency Wildfire Centre. Fueled by a record hot May, Canada is starting to meet its goal The fastest start to any fire season this century.
Map of active fires across Canada as of June 8, 2023. Red symbols indicate those considered “out of control.”
(CIFFC)
It may take until the fall or even winter before all of these Canadian fires are extinguished.
We are just heading into the peak months of the year for wildfires in the United States, especially in the West, which could heighten smoke concerns in the summer.
So, enjoy the heat relief from the cold summer fronts. But keep in mind that they may sometimes bring air that you may not want to breathe for a long time or want into your home.
More on Weather.COM:
How to protect yourself from forest fire smoke
Build your own air purifier for smoke
Fire weather forecast for summer 2023
Will wildfire smoke become more common in northeastern US cities?
What is the role of climate change in Canadian wildfires?
Jonathan Erdmann is a senior meteorologist at Weather.com, and has been an incurable weather geek ever since a tornado missed his childhood home in Wisconsin when he was seven years old. Twitter And Facebook.
The Weather Company's primary journalistic mission is to report on breaking weather news, the environment, and the importance of science in our lives. This story does not necessarily represent the position of our parent company, IBM.
