The Canadian prairies are rather dry, especially during the winter months. There’s not much precipitation and humidity is often very low, cracking skin and boosting the sale of epidermal moisturizers. It’s so dry that at times snow actually evaporates — not melts, evaporates. There are rare occasions when it’s a little more humid and even rarer occasions when everything works together to give you the amazing spectacle of Hoar frost.
Hoar frost (aka hoarfrost or radiation frost) refers to white ice crystals, deposited on objects such as branches, leaves and wires. These crystals form by condensation of water vapor to ice on cold, clear nights. Sometimes the hoar frost is so heavy it resembles snow, except that when you look at carefully, these are clearly ice crystals that have formed.
The name hoar comes from an Old English term meaning to “show signs of old age”, because the frost makes trees and bushes look like white hair.
Recently we had a day of superb Hoar frost formation in Calgary. It was very cold outside but I pulled out my parka, grabbed the camera and tried to get a few photos of this phenomena, which I hope you enjoy.
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