A meandering river of air turns into a waterfall
One of the ways to think about a vortex is to flush your toilet and watch the water swirl. If it swirls clockwise, maybe you are in the Northern Hemisphere, and if it swirls anticlockwise maybe you aren’t. Then again, maybe it is just your toilet.
While the Coriolis effect is a real phenomenon that affects large-scale systems like weather patterns and ocean currents, it does not affect water swirling in toilets or sinks. Swirl direction results from the drain design, not its location relative to the equator.
On the other hand, the Earth’s rotation exerts a powerful pull on the larger systems outside your bathroom. A massive air vortex forms in the late summer and autumn as the polar regions begin to receive less sunlight. The decrease causes the air over the poles to cool, which creates a temperature difference between the North Pole and the warmer mid-latitudes. The Coriolis effect deflects this moving air to the right in the Northern Hemisphere, resulting in a counterclockwise rotation — an atmospheric river.
Under typical conditions, the polar vortex maintains a relatively smooth, circular shape centered over the pole…