Mammatus Clouds
Mammatus clouds, or mammary clouds, earned their name because they resemble udders. These clouds often appear along with severe stormy weather or tornados; pilots avoid them due to turbulence. They are formed by cold air sinking in pockets, causing their unique shape as hot air rises in tandem. These clouds were first sighted in 1894. They may be pretty, but they're definitely bad news.
Hard Rime
This brave man scaled a cell phone tower to do maintenance after an ice storm. When condensed water droplets freeze on surfaces, it is known as hard rime. Hard rime forms in the direction of the wind. It can often be found on planes, trees, towers, and other tall structures that are exposed to the elements.