Thursday, May 30, 2013

What Causes a Thunderstorm?

It's springtime, and here that means thunderstorms! Last year when we talked about weather we made our own weather in a jar.  This year we decided to talk a little more about why storms actually form.

While in St Louis, we saw this fun demonstration at the Science Center that showed what happens when a thunderstorm occurs.  So what does happen? A cold air front runs into a warm air front forcing it to go up and causing unstable air. Then you get a thunderstorm. Back to the experiment, we are using colored water to represent the warm and cold air masses.  Now I tried this exactly how I remembered it with warm and cold water, and you know what I got? Purple water. So I tried hot and cold water and got... purple water. So I tried hot water and ice and got... purple water. Finally I tried warm water and ice and got a thunderstorm! Well not exactly, but you can see the general idea of how that unstable air is formed.

So start by adding some blue food coloring to water in a ice cube tray and freeze. Once the cubes are frozen fill a plastic shoe box half full with lukewarm water (remember the lukewarm part or you will end up with purple water).

Put a few drops (3 or 4) of red food coloring on one side of the shoe box. Then add two ice cubes to the opposite side. Watch what happens!

The water soluble food coloring disperses into the surrounding water while the ice slowly melts sending very cold blue water into the container and chilling the surrounding water.

As they meet you can see the colder, blue water forcing the warmer red water up. Right at that point, where the two are meeting and the blue is pushing the red up, is where you have your thunderstorm

And if you want to see it again you just dump it out and start over! I know my girls and I did it 4 times, and that was after we got the right combination! Definitely a fun, simple way to study thunderstorms!