**** Info via Environment Canada
Hoar Frost versus Rime Ice
Ever heard of hoar frost?
It is a type of frost with a feathery appearance. Hoar frost forms when the water vapour in the air condenses onto a solid surface below freezing. It usually forms under a clear cold night. The word “hoar” comes from old English and refers to the old-age appearance of frost – how the ice crystals form makes it look like white hair or a beard. It is delicate and can easily be blown away.
Hoar frost.
What is rime ice?
Rime ice forms when below-freezing water droplets settle onto an exposed surface. It forms when there is freezing fog and wind. Sometimes rime ice can be transparent, homogenous and ice-cube-like, which meteorologists call hard rime or clear ice. At other times, rime ice can appear similar to hoar frost with a milky and crystalline structure like sugar, known as soft rime. When hard rime ice is thick, the trees can become heavy, and it can even cause problems with power lines.
Rime ice.
Either way, the two phenomena produce icy trees and beautiful winter scenery, especially when the sun is shining!
