This chapter examines the vertical structure of midlatitude cyclones.  We look at the jet stream, divergence, upper level troughs and ridges that support the stages in the life cycle of midlatitude cyclones.  Vorticity is introduced which is important in understanding vertical motion and the strengthening of storms.

Local and synoptic scale wind systems are discussed.  These wind systems, such as a monsoon, are driven by temperature differences and a thermally driven circulation.  The wind regimes examined are the sea/land breezes, mountain/valley breezes, the Asian Monsoon and the North American Monsoon.

Once a learner has completed this chapter, they will be able to:

1. Outline the lifecycle of a midlatitude cyclone.

2. Understand the vertical structure of midlatitude cyclones.

3. Name the paths that midlatitude cyclones frequently travel across North America.

4. Describe the characteristics of a monsoon.

5. Describe the mechanisms which cause sea/land and mountain/valley breezes.