– Clear container filled 2/3 of the way with lukewarm water
– Red and blue food coloring
– An ice cube (a spoon for convenience)
Fill your clear container about 2/3 of the way up with lukewarm water. Next, put 4-5 drops of red food coloring in one end of the container. This red water will represent the warm air. Now, put 2-3 drops of blue food coloring on an ice cube, or freeze water into a cube of ice with food coloring already in it. This will represent the cold air that comes with a cold front. What you will see is the blue water sinking to the bottom, and sliding below the red water. This is an example of how cold air sinks and warm air rises above it.
What happens when a cold front moves into an area where there is warm air? Cold air is more dense than warm air, so it will sit closer to the ground. When it moves into an area of warmer air, that warm air rises because it is less dense. As the warm, moist air rises, it cools, condenses and forms clouds. Often times those clouds will bring precipitation and depending on other weather factors, can produce thunderstorms.