Each statement represents a primary learning objective for parts of this unit. After you complete the unit, you should be able to:

• Summarize the six processes by which water changes from one state of matter to another and, for each, indicate whether energy is absorbed or released.

• Write a generalization relating air temperature and the amount of water vapor needed to saturate the air.

• Describe adiabatic temperature changes and explain why the wet adiabatic rate of cooling is less than the dry adiabatic rate.

• List and describe the four mechanisms that cause air to rise.

• Describe how atmospheric stability is determined and compare conditional instability with absolute instability.

• Name and describe the 10 basic cloud types, based on form and height and contrast nimbostratus and cumulonimbus clouds and their associated weather.

• Identify the basic types of fog and describe how each forms.

• Describe the Bergeron process and explain how it differs from the collision–coalescence process.

• Describe the atmospheric conditions that produce sleet, freezing rain (glaze), and hail.

• List the advantages of using weather radar versus a standard rain gauge to measure precipitation.