| A | B |
|---|
| Air Mass | A large body of air with the same temperature and moisture content as the land below |
| Tropical | Warm air from the warm parts of the U.S.A. |
| Polar | Cold air from Canada |
| Maritime | Wet air from water |
| Continental | Dry air from land |
| Front | Boundary between two air masses |
| Warm Front | Warm air moves over cooler air (May cause rain showers and brings warm, moist air) |
| Cold Front | Cold air moves into warmer air (May cause severe weather and brings cool, dry air) |
| Stationary Front | Warm and cold air move past each other (May cause days of rain and unsettled weather) |
| Occluded Front | A warm air mass is between two cooler air masses (may cause cloudiness, rain or snow) |
| Cyclone | Low pressure system; warm, moist air; and cloudy skies |
| Anticyclone | High pressure system; cool, dry air; and clear skies |
