1. Chapter 9 The Water Cycle
Lesson 4: How can weather be predicted?

2. Air Mass- A large body of air that has a similar temperature and moisture level.
Cold Front- The boundary where a cold air mass moves under a warm air mass.
Warm Front- The boundary where a warm air mass moves over a cold air mass.
Barometer- A weather instrument used to measure air pressure.
Anemometer- A weather instrument that measures wind speed.
What kind of air mass forms over water?
Moist
Is the temperature of an air mass that forms near the equator cold or warm?
Warm

3. What causes weather to change?
Moving air masses cause weather changes.
When does a warm air mass form a warm front?
When it moves and pushes against a cold air mass.
When does cold air mass form a cold front?
When it moves and pushes against a warm air mass.
What are the effects of a cold front?
Thunderstorms and cooler weather are the effects of a cold front.

4. Cirrus Clouds- Cirrus clouds are found at high altitudes and is usually made up of fine white crystals. Usually indicates cool fair weather.
Cumulus Clouds- Usually formed by rising unstable air masses. Clouds are common on clear, warm days.
Stratus Clouds- Low-altitude, horizontal, gray clouds. Often occur along warm fronts.
What is a weather map?
A weather map is a graphic that gives information about weather conditions in the areas shown on the map.
What are some types of information shown on a weather map?
High and low temperatures, air pressure, wind speed, and wind direction.
How do meteorologists find wind direction?
By using a wind vane or a windsock.