An Air Mass is a large volume of air which travels from one area to another. The weather an air mass brings is determined by the region it has come from and the type of surface it has moved over.
There are 5 main Air Masses which affect The British Isles. You will need to be able to identify them and their characteristics.

The two pieces of information above will help you name the air mass and describe its characterists. The basic ideas are as follows:
| Source Area | Characteristics |
|---|---|
| Land | Dry |
| Oceans | Wet |
| Tropics | Warm |
| Arctic | Cold |
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