1. Earth’s Weather
Weather – state of the earth’s atmosphere at a certain time and place
Climate – the year-round weather typical of a certain place

2. Understanding Weather
A. Factors Causing Weather 1. Sun’s energy 2. Water vapor B. Changing States 1. Increasing energy Evaporation – the rate of evaporation is directly related to temperature

3. C. Returning to a liquid a. condensation b. dew c. frost

4. Clouds and Fog
1. Cloud – water vapor in the air condenses into tiny droplets of water
2. Types of clouds
a. Cumulus – “to pile” or “to heap”
b. Stratus – “layer”
c. Cirrus – “wisp” or “curl”

5. Water vapor condensed in a layer of air near the ground
FOG
Water vapor condensed in a layer of air near the ground

6. Air Masses a. Temperature b. Humidity c. Pressure
Factors affecting air mass
a. Temperature
b. Humidity
c. Pressure

7. Fronts and Weather 1. Fronts Two air masses fighting for supremacy
2. Cold front
Cold air moves into area covered by mass of warmer air
3. Warm front
Lighter warm air meets a cold air mass