Why do clouds cause turbulence?

When an airplane hits clouds, don’t be surprised by the shaking – it’s a natural result of colliding with the air currents.

Within clouds, the air is heterogeneous: warm air rises because it is lighter, and cold air descends because it is heavier.

These rising and falling currents interact with each other to create swirls.

The speed of these currents can reach 50-100 km/h (31-62 miles).

It is these invisible phenomena that create the turbulence you see in this video.

Fortunately, for modern airliners, this is just a normal flight moment that does not jeopardize safety, although it does add a bit of extreme. 

 Why do clouds cause turbulence?