1. What is weather?

2. What words/images come to mid when you think of the word “weather”? You can make a list of words, draw a picture or write your ideas in sentences. (2 minutes)

3. What is weather? Weather is the state of the atmosphere at a specific place and time. When we discuss the weather, we are talking about conditions like temperature, air pressure, wind and humidity.

4. Weather Factors 1) Air Temperature: Air is made up of molecules that are always moving. Temperature measures how fast the molecules in air are moving. High temperature = molecules moving quickly Low air temperature = molecules moving more slowly

5. Weather Factors 2) Wind: Wind is air moving in a specific direction. Warm air rises and expands. It has low atmospheric pressure. Cooler air is dense and sinks. It creates higher atmospheric pressure. Wind occurs because air moves from areas with high pressure to areas of low pressure.

6. Wind movement

7. Weather Factors 3) Humidity: Humidity is the amount of water vapor that is in the air. More water vapor can be present when the air is warm than when it is cool.

8. Show What You Know! 1)On Monday, the temperature was 52°F. On Wednesday it was 39°F. On which day were the molecules in air moving more slowly? a)Monday b)Wednesday c)They were moving equally fast on both days.

9. 2) Which of the following statements is true? a)Warm air is more dense than cool air and tends to sink. This creates low air pressure. b)Warm air is less dense than cool air and rises. This creates low air pressure. c)Warm air is less dense than cool air and rises. This creates high air pressure.

10. 3) Wind is created by a)The rotation of the Earth b)The motion of molecules in the air c)The movement of air from areas of high pressure to areas of low pressure

11. 4) If you hear a weather forecaster say that it is going to be a humid day, what does that mean? (turn and talk)