2. What do clouds have to do with weather?

4. What is it? - A measure of the amount of water vapor in the air.

5. Relative Humidity -The percentage of water vapor in the air compared to the maximum amount the air could hold

6. Relative Humidity is measure d using a psychrom eter WET DRY

7. How it works: -If the relative humidity is high, the water on the wet bulb will not change much. -The relative Humidity can be found by comparing the temperatures on a chart like this one.

8. How Clouds Form -Water vapor in the air becomes a liquid or ice crystals

9. Condensa tion -As air cools, the amount of water vapor it can hold decreases. -Some of that water vapor condenses to form a liquid.

10. What is Dew Point? -The temperature at which condensation begins

11. To Condensation -For water vapor to condense, tiny particles must be present so the water has a surface on which to condense. -Salt crystals, dust from soil, & smoke.

12. Types of Clouds Three Main Types -Cirrus -Cumulus -Stratus

13. Cloud Classification -Clouds are classified by their shape and altitude -Each type of cloud is associated with a different type of weather

15. Cirrus -Wispy, feathery clouds -Have feathery “hooked” ends -Form only at high levels (above 6 km) -Made of ice crystals

16. Stratus -Means “spread out” -Usually cover most of the sky

17. Cumulus -Means “heap” or “mass” -Look like fluffy, rounded piles of cotton -Usually indicate fair weather

18. “-nimbus” -Means “rain” -As stratus clouds thicken, they may produce rain and would be called “nimbostratus” -Cumulus clouds that are tall with flat tops often produce thunderstorms and are called “Cumulonimbus”

19. Cirrocumulus -Look like rows of cotton balls -Often indicate a storm is on the way

20. “alto-” -Means “high” -Form between 2 and 6 km. -Main types are altostratus and altocumulus.

21. FoG -Cloud that forms on or near the ground