Weather

1. SCIENCE
CHAPTER 6 WEATHER
SECTION 1
WATER IN THE AIR
PG 170-177

2. Weather
• Condition of the atmosphere at a given moment.
(What is it like outside right now?)

3. Water Cycle
•Water cycles through Earth’s atmosphere.

4. Water Cycle
•Evaporation – water changes into water
vapor (evaporates)
•Condensation – water vapor changes from a
gas to liquid (condenses)
•Precipitation – liquid and/or frozen water
falls from the sky
•Runoff – water moves around Earth

6. Humidity
•Humidity is the amount of water vapor in the air.
•As water evaporates, humidity of air increases
•Air with a higher temperature can hold more
water vapor.
•Air that can’t hold any more water is saturated.
•Saturated air has 100% relative humidity

8. Factors Affecting Relative Humidity
1) Changes to amount of water vapor in air
adding more water vapor increases relative
humidity
2) Increase or Decrease of Air Temperature
Air that is colder has a higher relative
humidity
 Air that is warmer has a lower relative
humidity

9. Condensation
•Process when water
vapor changes into a
liquid
•Air must be saturated
for condensation to
occur.
•Must be a surface for
condensation to occur.

10. Dew Point
•The temperature at which water vapor
condenses to a liquid

11. Clouds
•A collection of
millions of tiny
water droplets.
•Clouds are classified
by form and
altitude.

13. Precipitation
•Water falls back to
Earth as a liquid or
solid.
•Tiny water droplets
combine to form a
rain drop.
•When the rain drop is
too heavy, it falls.