Meteorologists: Don't expect more smoke from Minnesota

Meteorologists from the National Weather Service said it might not have been rare for smoke from a Minnesota fire to reach the Chicago area, but the concentrated haze that filled the suburbs this week was in a way the perfect storm.

“It's not rare that smoke would eventually reach us here because something like volcanic ash can travel hundreds of thousands of miles before it is dissipated in the atmosphere,” said National Weather Service meteorologist Rose Sengenberger.

“But to receive the smell and the haze we had yesterday is definitely a rarity. To see how concentrated it was, to have it actually cause breathing problems, that's what was rare about it.”

Wednesday's mixture of heavy clouds and rain cleared lasting particles out of the atmosphere, and meteorologists do not expect the weather patterns this week to send any more smoke toward Illinois.

“It is just so rare. You have to have the precise balance of the wind direction and atmospheric setup for that to occur,” said meteorologist David Beachler. “You would probably see that once in 1,000 times.”

The huge Pagami Creek wildfire in northern Minnesota, more than 400 miles away, was sparked Aug. 18 by a lightning strike near Ely, Minn., in the northeastern part of the state.

“The more interesting fact is that the smoke, where it was in the air hood in Minnesota, went up into the atmosphere, came across much of Wisconsin not posing any problems, and when it got to North Illinois the air was sinking at a rapid rate,” Beachler said. “It really didn't thin out or dissolve.”

Lighter winds and cooler temperatures delivered encouragement Wednesday as firefighters in Minnesota continued their efforts to contain the blaze that was in a “pause mode” — days after it moved at breakneck speeds, swallowing roughly 160 square miles of forest along the Minnesota-Canada border.

The fire in the Boundary Waters Canoe Area Wilderness is one of the largest on record in the state, and just under half of the access points into the wilderness were closed to campers by midday Wednesday.

Meanwhile, environmental officials issued an air pollution warning for the Chicago area Wednesday, as some smoke continued to drift in. The air quality was thought to be unhealthy for people with lung and heart problems and active children and adults. The smoke contains fine particles, which can lodge deep in the lungs and enter the bloodstream.

Residents were still being told to keep indoor air as clean as possible, by running the air conditioner and avoid vacuuming.