April 23, 2008
Provided and copyright by: Craig Schisan, Red Deer College
Summary author: Craig Schisan
In mid-October, 2007, Red Deer, Alberta experienced its first taste of winter, or was it the last sip of summer? Light rain began to fall during the night, and the temperature started to drop to near freezing. There was just enough heat in the ground and other objects, such as my car, that the rain didn't freeze; it just made everything wet. At some point, while the roof of my car was still very wet, the temperature dropped below freezing, and the ice crystals shown above formed. The feathery nature of the crystals gave them the appearance of frost, but this was actually clear ice, at least 1 mm thick, and not frost. Had the temperature been slightly colder, freezing rain would have occurred, forming a uniform, bumpy surface where raindrops froze on contact. This was freezing water rather than freezing rain.