Weekend Meteorologist Joseph Dames

PORTLAND, Ore. (KOIN) – Today we are going to talk about something you may notice each and every day around you, but you didn’t know it was happening. Something you’ve definitely seen at a carnival and you may even have some toys around the house that demonstrate this topic, and that general idea is force. What is that?


In this lesson we’re examining apparent force, which can be defined as mass times an acceleration. Whoa, that sounds like a big equation! Don’t be intimidated by the math. Let’s focus on examples.

Have you ever had a ball on a rope and spun it around over your head? Real fast and you just watch it spiral up there but it doesn’t go flying? What is keeping that ball going around and around and not shooting well over the fence? Well, you’re pulling it back with your hand because it is attached to you.

Have you ever tried skipping over a chained ball? You may have a similar toy at your house where you spin the the ball around your ankle as you whip it around just above the ground. This is the same concept! How does that ball keep on going around and what is preventing it from moving in a non spherical pattern?

I’m sure you have figured it out by now, there is a force in action. What should we call it? Today we will focus on one specific force called centripetal force!

Centripetal Force: the acting force that drives inward.


Where can we spot this in the scope of our weather? We can start with this image below. We show these mid-latitude cyclones frequently in the winter.

However, what keeps wind blowing around an area of low pressure? Well it is constantly accelerating because it continues to change direction towards the area of low pressure. This is actually called centripetal acceleration. Check out the image of the low pressure above, you can see how everything is spiraling into the middle of that center of low pressure. That is because the net force acting on the wind is directed toward the center of the low pressure, and that will keep the air moving inward.

I hope this sparked an interest in your thoughts about force. Next time your at the park or carnival, you have an idea of what is going on and how it also applies to our weather!

There is more! If you’re interested in the motion of air and what is pressure, you can go to this lesson of Weather Kids.