CHICAGO (WLS) -- Freezing fog is when fog forms, but the air temperature is below freezing.
The tiny little rain droplets remain as liquid even in this sub-freezing environment. But when they come in contact with surfaces like trees and bridges that are below freezing, those raindrops freeze.
[Ads /]
This can form a glaze of ice creating slick conditions.
RELATED:
Lightning safety tips
[Ads /]
What is the difference between a funnel cloud and a tornado?
Which is worse: Watch or Warning?
How do tornadoes form?
[Ads /]
What is a microburst?
What is an outflow boundary?