There are two main things that cause weather, the earth and the sun. When sunlight leaves the Sun, it travels through space until it reaches the Earth. Sunlight adds heat to the Earth's surface. It warms up land, air and water.

The Earth goes through a number of motions in relationship to the sun. The Earth rotates or spins in a circle in space. As rotation occurs, different parts of the world will be exposed to sunlight at different times of the day. The part that is exposed to the sun is experiencing daytime. The part that is away from the sun is experiencing nighttime. The earth takes 24 hours or one day to rotate around the sun.

You can have the students experience rotation by placing the yellow ball in the center of the circle that the students make. Make sure they give themselves plenty of room to "rotate", arm's length apart. Each student will be the Earth, their heads being the North Pole and their waists being the equator. Above their waist is the Northern Hemisphere and below their waist is the Southern Hemisphere. Have them imagine that a line is running from their toes to their heads representing the rotation axis of the Earth. Instruct the students to stretch their arms out to their sides while they are facing the sun in the center of the circle. Ask them what time their noses represent. Noon because the sun is in the middle of their stretched out arms. Ask them what time the back of their head represents. Midnight because the sun is on the opposite side of the Earth. Direct them to stretch out their right hands with thumbs up to represent Eastward and their left hands in a fist with thumb tucked inside. Ask the students which direction does the sun set. West. Have the students rotate Eastward (towards outstretched hand). Have them stop when their left hand (West) is facing the sun. This is sunset. Which way does the sun rotate? Towards the East.

The Earth undergoes another motion called revolution. Revolution is the motion of the Earth as it moves around the Sun. The Earth takes 1 year (365 days) to revolve around the sun. The Earth moves around the Sun in the shape of an ellipse or an egg shape rather than the shape of a circle. As the Earth revolves around the Sun, the Earth's axis is tipped towards the Sun one part of the year, and away from the Sun the other part of the year.

Have one student hold the inflatable globe. Have another student hold the dowel rod. Have a third student hold the flashlight. Turn the flashlight to the ON position to represent sunlight. The Earth will revolve or move in an ellipse around the Sun. Have the top part of the axis face the Sun. Rotate the globe so that Virginia is facing the Sun. Have the student holding the dowel rod place the rod between the flashlight and the globe illustrating that the sun is pointing directly on Virginia, which is in the Northern Hemisphere. The angle of sunlight is direct. Now have the student with the dowel rod place the rod in the Southern Hemisphere. The angle of sunlight is indirect. The Northern Hemisphere is illustrating summer and the Southern Hemisphere is illustrating winter. Have the Earth revolve to the other side of the Sun and repeat the same activities. You will notice that the Northern Hemisphere is in indirect sunlight, winter, and the Southern Hemisphere is in direct sunlight, summer. Once you understand a little bit about the Sun, seasons and the Earth's motions, it is easier to understand the weather. Changes in the weather are merely changes in the atmosphere.

Take a look at the weather map. The blue lines under the triangles are called cold fronts. A cold front is the beginning or leading edge of a huge moving mass of cold air. The red lines with half circles on top are warm fronts. A warm front is the leading edge of a huge mass of warm air that is moving across the country. The big H's mean high pressure and the big L's mean low pressure. Low pressure is a mass of light air, or air that is moving up into the sky away from the ground. High pressure is a huge mass of heavy air that is moving towards the ground from above. Low pressure is associated with light air and high pressure is associated with heavy air. We tend to have stormy, cloudy weather connected to low-pressure areas.

Have the students look at a current weather map from the newspaper. Identify the weather symbols and meaning on the map. Have the students make their own weather map and present it to the class as a meteorologist would during a weather forecast by explaining the different symbols and meanings.