2. What is Weather? 1. 1. Wind 2. 2. Temperature 3. 3. Humidity (moisture in the air) 4. 4. Air Pressure The condition of the atmosphere in a certain place at a certain time. 4 Elements of Weather:

3. Atmosphere 600 kilometers above Earth What What do you call Earth’s air; the air around you and above you? Amixture of gases 78% 78% Nitrogen 21% 21% Oxygen 1% 1% Other gases

4. Land and Water The __________ directly absorb heat energy from the sun.

5. What Causes Seasons? Caused by Earth’s tilt and Earth’s revolution (orbit) around the Sun.

6. What is wind and heat? Name two factors that affect evaporation. Name two factors that affect evaporation. What changes What changes liquid water to a gas (water vapor)?

7. What is humidity? The amount of water vapor (water in its gaseous state) in the air. The amount of water vapor (water in its gaseous state) in the air.

8. What is precipitation? Moisture that returns to the earth’s surface from the atmosphere. Moisture that returns to the earth’s surface from the atmosphere. Rain, Sleet, Hail, Rain, Sleet, Hail, and Snow and Snow

9. Rain, sleet, hail, snow Can you name 4 forms of precipitation? Can you name 4 forms of precipitation? (moisture that falls from the sky to Earth’s surface)

10. What are clouds? They are collections of tiny droplets of water or ice. They are collections of tiny droplets of water or ice. They form when water vapor molecules condense. They form when water vapor molecules condense.

11. 0 ˚C =freezing 100 100˚C =boiling 0 ˚C =freezing 100 100˚C =boiling Give the freezing and boiling temperatures for the Celsius scale Give the freezing and boiling temperatures for the Celsius scale

12. What are days and nights? They are caused by the Earth’s rotation (spinning) They are caused by the Earth’s rotation (spinning) (24 hours to rotate one time)

13. What is winter? The north pole is tilted The north pole is tilted away from the sun. The sun is low in the sky. The sun is low in the sky. What season is it? What season is it?

14. the West to the East In the United States, our weather usually moves from… In the United States, our weather usually moves from…

15. What causes seasons? The earth’s tilt. The earth’s tilt. The earth’s revolution (path/orbit around the sun) The earth’s revolution (path/orbit around the sun)

16. What is a weather forecast? A prediction of the weather to come. A prediction of the weather to come.

17. What is a meteorologist? A person who studies the weather. A person who studies the weather.

18. What is the Fahrenheit scale? 32˚F is the freezing temperature 32˚F is the freezing temperature At 212˚F, water will boil At 212˚F, water will boil

19. What are clouds? When water vapor cools high the sky, these will form.

20. The Water Cycle The The Earth uses the same water over and over again. Evaporation, Evaporation, condensation and precipitation are part of this process.

21. What is Condensation? This happens when water vapor changes to liquid water. This happens when water vapor changes to liquid water. a. Evaporation b. Condensation c. Saturation

22. Solid Liquid Gas Name the 3 states of water. Name the 3 states of water.

23. Weather Suppose Suppose it is raining and cool where you are. That’s your weather today. The The condition of the air around you.