Weather experiment: How do thunderstorms form?

ITV Weather Meteorologist Chris Page explains how thunderstorms form in our atmosphere

What does the experiment show?

For a thunderstorm to form in our atmosphere, we need three key ingredients:

1. Moisture - and warmer air can hold more moisture than cool air

2. An unstable atmosphere

3. A lifting mechanism - such as the sun's energy heating the ground which then heats the air above it on a hot day

In this kitchen sink science experiment, that you can try at home, the blue ice cubes represent cold or cool air sinking as it's denser.

Whereas the red colouring represents warm less dense air rising.

The reaction between these two air masses is caused by convection. This is how moisture and heat is carried into the upper part of our atmosphere.

The energy from convection makes our atmosphere unstable. And it's this instability that allows warm moist air to rise leading to thunderstorms.

Demonstrating atmospheric convection using food colouring, water and ice Credit:

Try it for yourself and see if you can make a better result than Chris did!

You will need

  • Ice cube tray

  • Clear glass or plastic container

  • Red and Blue Food colouring (avoid getting it on your hands and clothes as it will stain)


1. Mix the blue food colouring with water, add it to the ice cube tray and freeze

2. Once frozen, add lukewarm water to clear container about 1cm from the top

3. Add the blue frozen ice cubes to one side of the container and a few drops of red food colouring to the other.

4. Watch the convection take place and see how the two colours interact with each other due to a difference in temperature.

Top tip: Make sure the water isn't too hot as your ice cubes will melt too fast and you'll be left with a messy pool of purple liquid. Good luck!