What is black ice?

Black ice usually forms overnight in winter in cold countries. It is almost perfectly clear, so it is difficult to see and therefore, extremely dangerous. There are none of the trapped air bubbles or swirls that make white ice translucent or opaque, and therefore visible. It is black because you can see the tarred or asphalted road surface underneath!

Black ice forms in conditions of fog, mist or even condensation of car exhaust. Heavy, pounding rain with wind that churns up the road surface produces the usual white ice.

Black ice can be present on a sunny but below-freezing day, when the sun warms up the road surface and the snow melts. Then, overnight, the melted snow and slush refreezes into a thin layer of black ice.

It might just look like a wet patch of road – until you drive over it.

 

Picture Credit : Google