Smoke from Canadian wildfires is pushing toward the Great Lakes and Northeast through Thursday, with air quality expected to turn very unhealthy where the plume drops closest to the ground. In northeastern Minnesota, the Pollution Control Agency has issued Air Quality Alerts for Two Harbors, Hibbing, Ely and the Grand Portage Tribal Nation.
According to the Canadian Interagency Forest Fire Centre, 32 wildfires sparked across mostly western Ontario on Monday, and 46 wildfires were burning out of control there. Several more fires sparked and intensified in northern Minnesota the same day, and the Camp Fire in Lake County jumped its containment lines and triggered local evacuations.
FOX Forecast Center
The FOX Forecast Center said a major shift in wind direction over the next 24-36 hours will allow heavy concentrations of smoke to pour into the Lower 48. It said the smoke will likely create milky, hazy skies across the Upper Midwest and Great Lakes beginning Wednesday morning, with the thickest bands bringing reduced visibilities.
“Under the thickest bands of the plume, reduced visibilities are possible, and air quality will likely become very unhealthy if the latest computer forecast models are correct,” the FOX Forecast Center said. Much of the smoke is forecast to remain elevated high in the atmosphere, but the same forecast also shows a growing signal for a 6-8 hour window when smoke could settle closer to the ground.
Pollution Control Agency
The alerts in northeastern Minnesota tell people in the affected areas to avoid prolonged outdoor activity. The sharpest air-quality decline is expected where the plume is thickest near the surface, not where the smoke stays aloft, so conditions can vary over short distances even within the same region.
“While much of the smoke is forecast to remain elevated high in the atmosphere, there is a growing signal that there could be a 6-8 hour window with smoke close to the ground,” the FOX Forecast Center said. The forecast points to a short stretch in which the sky may look only milky overhead while breathing conditions deteriorate at street level.
June 7, 2023
That kind of scene has a recent parallel: hazy conditions tied to the Canadian wildfires were seen across New York City on June 7, 2023. The comparison suggests the most visible change may arrive before the worst of the smoke reaches the ground, with the surface-level danger concentrated in the thickest bands of the plume.
For people under the alerts in Minnesota, the practical step is to limit time outside during the smoke surge and watch for the period beginning Wednesday morning, when the plume is expected to arrive across the Upper Midwest and Great Lakes.
