On Tuesday a large part of our state either saw or smelled smoke from a raging wildfire in the Boundary Waters Canoe Area in northern Minnesota. The smoke was particularly easy to detect in the northern parts of Wisconsin, but it spread southward during the day and eventually led to the Milwaukee Brewers deciding to close the Miller Park roof on an otherwise delightful early fall evening just to keep the smoke out.
This was a good decision, as prolonged exposure to smoke plume from wildfires is a health hazard. In fact, officials were recommending that people in the northern parts of the state limit their outdoor activities in the face the invading smoke.
The fire responsible for this pall of smoke was actually initiated by a lightning strike in the Boundary Waters on August 18 and has burned, slowly and over a relatively small portion of that unpopulated area, for nearly a month before a vigorous cyclone passed just to its north over the weekend. The strong winds associated with that storm fanned the flames, resulting in the fire racing 16 miles east between Monday and Tuesday, quadrupling in size. The same storm accounted for our abrupt and welcome change to fall-like conditions early this week.
The weather is a major factor in the growth of wildfires as dryness preconditions the fuels at the ground and winds quickly spread the fire. Though not an everyday occurrence, long-range transport of smoke from remote fires is far from unusual. The proximity of this fire to our state accounts for the pungent nature of this remote smoke event.