2Empty Plastic Bottles - I used 2-liter size for this experimentbut you can use any size clear plastic bottle. Both bottles will need to be the same size.
Water
Duct Tape
Food Coloring. The food coloring is optional. HoweverI think that it is easier to see the tornado when the color has been added. I chose black to look more like a dark storm, but you can choose any color that you would like.
Instructions
Step 1. Pour the water into the pitcher.
Step 2. Next, add the food coloring.
Step 3. Mix together.
Step 4. Use the pitcher and begin filling the bottle.
Step 5. The amount of water should be about 3/4 full.
Step 6. Align the empty bottle directly on top of the bottle with the water in it. Then use the duct tape to secure the 2 plastic bottles together. To create the tornado, turn the bottles full of water over and swirl the water clockwise. Then a tornado funnel shape will form as the water moves from the top bottle to the lower bottle.
Notes
You probably already have most of these supplies at home. This experiment is so simple and does not require much to do.