Where is the coriolis effect the largest

Moving from the north pole toward the equator: This is the easiest direction to visualize and one you have seen in the above videos. Imagine a plane leaving the north pole and aiming directly for a certain location. The entire time it is flying south toward its destination, the earth's surface is moving out from underneath it, toward the east. The plane will end up west of (or from the plane's point of view, to the right of) its intended destination.

Moving from the equator toward the north pole:
This requires a little background information. An object at the north pole would not move, other than turning, as the earth revolves around the pole once in 24 hours. As you go further south, the earth is wider and wider, and the distance to be travelled in 24 hours is literally further, so objects at the surface of the earth are moving faster. Although we do not sense this type of movement, an object at the equator is actually travelling a dizzying 1,018 mph to the east in order to rotate around the earth's axis every day.

To visualize the Coriolis Effect when traveling from south to north in the northern hemisphere, we must consider the fast starting speed of the airplane. Before it even takes off, an airplane leaving the equator and going to a city at 30 degrees north is moving to the east 136 mph faster than is its destination. As the plane flies northward, it also retains this eastward velocity, and continues to move toward the east faster than its destination is moving east. The plane will be east of its intended destination when it arrives at 30 degrees north. This is also a deflection to the right, from the plane's point of view.