Subject: Geography
Topic: Caribbean Weather Systems: Anticyclones
Grade: 11
Date: September 2021
Specific objectives: At the end of this lesson students should be able to:
 Define the term anticyclones
 Explain the weather conditions that are associated with anticyclones.
 Draw diagrams to explain how anticyclones work.
Caribbean Weather Systems: Anticyclones
https://www.youtube.com/watch?v=v8086busfvq
An anticylone (also known as a high pressure system) is a large area of high
atmospheric pressure. Anticyclones may be thousands of kilometers in
diameter. The pressure within an anticyclone is 1000 millibars or more. Light
winds circulate around the central area of high pressure in a clockwise direction in
the northern hemisphere. Within the anticyclone air is descending.
Air descends in an anticyclone.
As the air descends, it is compressed and warmed. These conditions are not
suitable for cloud formation. Therefore, anticyclones are associated with long
periods of sunny or fair weather with few or no clouds and no rainfall. There is
usually a light wind. These conditions generally persist for several days or even a
few weeks.
An anticyclone off the southern coast of Australia. (Photo by NASA)
During the northern hemisphere winter, anticyclones form over North America and
these may extend over parts of the northern Caribbean. During the northern
hemisphere summer, an anticyclone develops over the mid-Atlantic and may
extend over parts of the Caribbean.