Air Masses & Fronts (cont'd)

Tropical air masses are warm and originate in tropical regions or over mid-latitude continents during the summer. Usually these will be created just north or south of the equator.

Tropical Continental air masses are warm and originate over a land mass (continent). These air masses will be very warm with low moisture content (low dew point).

Tropical Maritime air masses are warm and originate over water (oceans). These air masses will be very warm with high moisture content (high dew point).

Notice the source regions of the 2 types of tropical air masses. The air masses with high moisture always originate over large areas of water. In the example above it happens to be the Gulf of Mexico.