Hurricane Swirl
SCIENCE

Materials

(for the whole class)

• water
• shallow cake pan
• cornstarch
• food coloring
• spoon
• paper and pencil (optional)

A hurricane is a huge storm over the ocean that has winds and clouds swirling around its calm center. In this activity students will model the shape and pattern of those winds and clouds using water instead of air.

Directions

1. Stir a few spoonfuls of cornstarch into the pan of water. The amount doesn't have to be exact, it just needs to look milky.
2. When the water is more or less still, add one or two drops of food coloring into the middle of the pan. Have students observe the color's movement and pattern for a few minutes. (Your results will vary, but likely some color will sink at the center while some color will form a slow-moving spiral with additional tiny spirals along its arms.) Consider asking students to draw what they see.
3. Pull the spoon very slowly through the water. Ask: What follow in the wake of the spoon? (spirals) Again, consider asking students to draw what they see.
4. Erase the color by completely mixing it in and let the water settle. Then add two or three more drops of food coloring in the center.
5. This time try to use the handle of the spoon to make a circle around the drops. Is what happens different? (A spiral is created inside the path of the spoon handle.) Invite students to draw their observations, if desired.
6. Help students connect what's happening in the pan to how conditions in the atmosphere could cause swirling winds. Ask: Which would be more like a wider band of wind, the handle or round part of the spoon? (round) How did the speed of the moving spoon affect it?

Book Break

Read The Magic School Bus Inside a Hurricane by Joanna Cole (Scholastic, 1995). Ask students to pick out any interesting facts they find about hurricanes and other storms. Write the facts in question form on index cards and use the questions to hold a Hurricane Quiz Show in the classroom.