Rookie Weather Question

I visit the NOAA-NWS site often because I am the curious sort and like to know what is going on everywhere, especially with the weather.

One of the things I like to look at is the national satellite image, and looping it is particularly entertaining for me. No snickers please.

My stupid weather question is this - what causes weather systems to spin as they do?

Thank you for your extreme patience in answering what is surely a dumb question.

Bibliophile

I believe it is the earth's rotation that causes the "spin" in weather systems. Northern hemisphere storms spin clockwise and south hemisphere storms spin counter clockwise.

Imagine the earth is one huge skating rink. You're at the North Pole and decide to skate down to the equator. You might think that you would travel in a straight line, but your path would in fact be curved, because of the rotation of the earth.

Air moves towards low pressure systems and away from high pressure. They might normally travel in a straight line but instead get spun by the earth's rotation. Called the Coriolis Effect.

Yep, that's right - it's all down to that coriolis force

There's an article on it here