1. Weather Patterns Table of Contents Clouds Precipitation
Air Masses and Their Movements
Storms
Predicting the Weather

2. Clouds
How Clouds Form
Clouds form when warm, moist air rises and cools.

3. Clouds Cloud Types There are many different types of clouds. Cirrus
Cirrocumulus
Cumulonimbus
Altocumulus
Altostratus
Cumulus
Nimbostratus
Stratus
Fog

4. Clouds Clouds and Weather
What kind of weather can be predicted from each type of cloud?

5. Precipitation Rain Gauge
The rain gauge, measuring in centimeters, collects ten times the actual depth of rain that falls.

6. Precipitation Water Droplets
Cloud droplets condense to become larger droplets.

7. Precipitation Freezing Precipitation
What would be the air and ground temperature ranges for each type of precipitation?

8. Air Masses and Their Movements
Types of Air Masses
Air masses can be classified according to temperature and humidity.

9. Air Masses and Their Movements
North American Air Masses
Air masses can be warm or cold, and humid or dry.

10. Air Masses and Their Movements
Types of Fronts
What type of weather is brought by each front?

11. Air Masses and Their Movements
Cyclones and Anticyclones
Which image is a cyclone and which is an anticyclone? What is the air motion direction of each?

12. Air Masses and Their Movements
Which circles are low-pressure centers and which are high-pressure centers?

13. Storms Lake-Effect Snow
As cold, dry air moves across the warmer water, it becomes more humid as water vapor evaporates from the lake surface. When the air reaches land and cools, lake-effect snow falls. Which cities receive lake-effect snow?

14. Storms How Thunderstorms Form
A thunderstorm forms when warm, humid air rises rapidly within a cumulonimbus cloud. What is indicated by the blue and red arrows?

15. Storms
Hurricane
Where is the eye of the hurricane? Where are the strong and weak areas?

16. Storms
Hurricane strength is ranked on the Saffir-Simpson Hurricane Scale.

17. Storms Tornado Formation
About 1,200 tornadoes occur in the United States every year. Weather patterns on the Great Plains result in a “tornado alley.”
Key

18. Storms
Types of Tornado Damage

19. Predicting the Weather
Red Sky
Many people use creative thought to summarize their own observations of weather.

20. Predicting the Weather
Weather Map Symbols
The tables below show what various weather symbols represent.

21. Predicting the Weather
Newspaper
Weather Map
The symbols on this map show fronts, high-
and low-pressure areas, the
high and low temperature readings for different cities, and precipitation. The color bands indicate different temperature ranges.

22. Predicting the Weather
Weather Map