The Coriolis Force is a force that deflects moving objects to one side because of the Earth’s rotation. The object is still going straight but the Earth moves underneath it, making it look like it is moving to one side. In the Northern Hemisphere the Coriolis Force deflects objects to the right.

Experiment: Try this out!
Try rolling a ball across the floor of a spinning merry-go-round. The ball looks like it is deflected to one side because of the spinning merry-go-round. This is the same idea as the Coriolis Force.