WeatherTalk: Wet, cool soil has meant no dust devils this spring
Dust devils were plentiful at this time last year.
FARGO — Last year, at this time of year, much of our region was quite dry, with dry topsoil and a growing concern about summer drought. The weather pattern brought a stretch of warm days right around this time of May, with plentiful sunshine, light wind, and afternoon temperatures in the 70s and 80s. These conditions were ideal for dust devils. In relatively still air, rising columns of warm air will rotate and create a self-sustaining, small-scale low pressure system which picks up dust from the dry ground, making it visible.
Dry ground is key to the formation of dust devils because the dry soil is very efficiently heated by sunlight, allowing thermals to grow quite strong over any local hot spot. This spring's soggy, cool soils have not allowed dust devils to form, and will not allow any unless we get enough dry weather to let the topsoil dry out before the fields are covered in maturing crops.