FARGO — With so many large wildfires already burning across the Canadian Rockies and boreal forest, it is likely that there will be smoke in our region from time to time through the summer. The smoke from wildfires hundred of miles away tends to be thicker high in the sky instead of low to the ground. Hot air rises, for one thing, while trees and other terrain tend to scrub out a lot of the smoke particles near the ground. The choking surface smoke last Wednesday and Thursday was a special case.
A cold pool of air in the wake of a cold front moved over the fires in Alberta and Saskatchewan and came directly to us. Warmer air above the cold pool trapped the smoke near the ground and delivered it to our noses. A similar circumstance may happen again, but most of the smoke this summer will be high in the sky, turning blue skies to a milky white and making the sun look orange and weak.