1. How Do Clouds Form?
Clouds form as warm air is forced upward, expands, and cools until it reaches its dew point.
The water vapor condenses, forming water droplets that group together. When millions of these droplets collect, clouds form.

2. 3 Ways Clouds Form
#1 Clouds form when warm air is forced up in a convection current caused by solar radiation heating the Earth’s surface.
#2 Clouds form when warm, moist air is forced to rise over a mountain. The air cools and the water vapor condenses.
#3 Clouds form when 2 air masses meet. Warmer air is forced up over the cooler air. As the warm air cools to its dew point, the water vapor condenses, or gets together to form clouds.

3. How are clouds classified?
By SHAPE and HEIGHT

4. 4 main cloud types

5. CIRRUS CLOUDS - VERY HIGH CLOUDS MOSTLY MADE OF ICE CRYSTALS
- THEY LOOK VERY STRINGY, THIN, AND HAIR-LIKE
- USUALLY OCCUR IN FAIR WEATHER AND POINT IN THE DIRECTION THE AIR IS MOVING

6. Cirrus Clouds

7. CUMMULUS CLOUDS - VERY PUFFY AND LUMPY LOOKING CLOUDS
- THEY ARE LOW IN ELEVATION, THAT INDICATES WARM AND SUNNY WEATHER
- IF THEY ARE HIGH UP AND TALL, THEY CAN GROW INTO THUNDERSTORMS

8. CUMMULUS CLOUDS

9. STRATUS CLOUDS - FLAT SHEETS OF CLOUDS
- THESE CLOUDS CAN MEAN AN OVERCAST DAY OR STEADY RAIN AND DRIZZLE
- THEY MAY STAY IN ONE PLACE FOR SEVERAL DAYS

10. STRATUS CLOUDS

11. NIMBUS CLOUDS REALLY DARK AND LOW CLOUDS THAT ARE EITHER
PRODUCING THUNDERSTORMS OR ABOUT TO PRODUCE RAIN
- THEY ARE USUALLY A COMBINATION OF ONE OR MORE TYPES OF CLOUDS

12. NIMBUS CLOUDS

13. Prefixes for Cloud Height
Cirro: high clouds
Alto: middle elevation clouds
Strato: low clouds

14. Cirrostratus: high clouds that look like fine veils
Cirrostratus: high clouds that look like fine veils. They are made of ice crystals and sometimes appear to form halos around the moon or sun.

15. Altostratus: form at middle levels and look like thick veils or sheets of gray or blue. If they are not too thick, sunlight can filter through them. They produce light, continuous precipitation.

16. Nimbostratus: bring long, steady rain, and low to the ground
Nimbostratus: bring long, steady rain, and low to the ground. They often have streaks that extend to the ground.

17. Cumulonimbus: occurs when a nimbus cloud tows a cumulus cloud
Cumulonimbus: occurs when a nimbus cloud tows a cumulus cloud. Sometimes they release unexpected, giant thunderstorms.

18. Conditions necessary to form rain:
Air near the ground has to be warm to form water vapor. Then rain droplets will form.

19. Conditions necessary to form sleet:
Air near the ground has to be cold to form many small ice pelets. Then sleet will form.

20. Conditions necessary to form snow:
Air near the ground has to be cold to form snowflakes. Then snow will form.

21. Conditions necessary to form hail:
Hailstorms are pellets of ice that form as the ice nuclei go up and down in the cloud.