Scientists Accidentally Confirm That Jets Can Punch Holes in Clouds

How do you punch a hole in a cloud? Fly through it. Meteorologists had long figured that aircraft were part of the explanation for crazy-looking "hole-punch clouds" like this one. When propeller planes fly through a cloud, they thought, it can exert air pressure that cools water extremely quickly to produce ice. If water vapor condenses on that ice, snow falls from the sky and leaves a conspicuous cloud hole. Now, thanks to a happy accident, researchers confirmed that planes can cause these cloud holes, and that even jets, not just prop planes, can do it. Andrew Heymsfield, a scientist with the National Center for Atmospheric Research, was aboard a research plane near the Denver airport in 2007 when he unwittingly flew through a flurry of snow produced by a hole-punch cloud.