# Weather Prediction

SUMMER SIZZLES!

It’s just another hot summer day. For lunch you fix a grilled-cheese sandwich, down a soda, and have a popsicle for dessert. You decide to beat the heat and head for the pool. With towel in hand, you head out the door. Suddenly you realize the weather is dramatically different. A cool breeze glides in from the north. You change your plans. You don’t need the pool to cool off. Mother Nature is already taking care of it in her own way.

A CHANGE IS IN THE AIR!

How did the weather change so suddenly? Why was it blistering hot before lunch, and a bit chilly after lunch?

There are giant masses of air that move in the atmosphere over Earth. These air masses form over different parts of Earth and can be warm or cold. They can also be dry or moist. When two different types of air masses meet, a front forms. When a front moves over an area, the weather changes.

Let's Map it Out!

Using a newspaper weather map, do the following activities:

1. Locate a cold front on the map. Circle it in blue.
2. Locate a warm front on the map. Circle it in red.
3. Locate a stationary front ( a mix of a warm and a cold front). Circle it in another color.
4. Use the map to find any changes coming to the area where you live.

You're the scientist!

Cold and warm air act differently. How they act differently is difficult to see since they are invisible! Luckily you can use water to help. This experiment demonstrates what happens when cold and warm air meet. (The cold and warm water act a lot like cold and warm air.)

Materials:

• 9x13 inch glass baking dish
• Water at room temperature
• One cup of very cold, ice water
• One cup of very hot, tap water
• Blue food coloring
• Red food coloring

Procedure:

1. Fill the baking dish half full with the room temperature water.
2. Add a few drops of blue food coloring to the very cold, ice water.
3. Slowly pour the cold, blue water into the tub of clear water. (Pour very slowly)
4. Explain what happens. Draw a picture of what you observed.
5. Empty and replace the room temperature water in the baking dish.
6. Add a few drops of food coloring to the very hot, tap water.
7. Very slowly, pour the hot water into the tub of clear water.
8. Observe what happens and draw a picture to show your results.

In this activity the cold water sinks to the bottom. Cold water is heavier, or denser, than room temperature water. The hot water stays at the top. Hot water is lighter, or less dense, than room temperature water. This is also true of air. Warm air rises. Cold air falls.

When masses of cold and warm air meet, it causes changes in the weather. Cold fronts produce violent weather such as blizzards and thunderstorms. Usually when a cold front moves over an area, the weather produced lasts for two to twelve hours. Warm fronts also produce stormy weather. However, the weather associated with warm fronts is not as severe as cold front weather. Storms associated with warm fronts may last for several days.

Download the plug-ins: , and . (The QuickTime plug-in is needed to play sounds and movies correctly.)

Want to share photos of you or your friends doing this activity? Send it in an e-mail with the following information:

1. The title of the activity