A desert is dry. It does not produce a lot of water vapor. An air mass that forms over a desert will have low humidity.
The desert receives an extremely low amount of precipitation (rain, snow, etc. that has fallen at a place in a given period) or lack of water. This would make an air mass that forms over a desert have low humidity (The air mass would not be moist).
Continental tropical.
About 32 degrees ...
Hot, dry and low pressure forms over hot deserts. Known as a tropical continental air mass.
Mountains act as a focus for rising air currents that contain some humidity. As the air rises it forms clouds over the mountains and rain occurs there before it moves over the desert.
A continental tropical air mass typically has low humidity and high air temperature. This air mass forms over hot and dry regions, such as deserts, and brings warm and dry conditions when it moves into different areas.
A continental tropical air mass is dry and warm because it forms over hot and dry land areas. As the air mass sits over these regions, it heats up and loses moisture, resulting in low humidity levels and warm temperatures.
Maritime tropical air masses form over tropical waters. These air masses are warm and moist due to the high temperatures and high humidity of the water below them. They can bring heat and humidity to regions they move over.
An air mass is a large body of air with uniform temperature and humidity characteristics. It forms over a specific region and acquires its properties from that area. When an air mass moves to a different region, it can bring its weather characteristics with it.
A warm and dry air mass is typically classified as a continental tropical air mass. This air mass forms over hot and dry regions on continents, leading to warm temperatures and low humidity.
An air mass classified as cT usually forms over hot and dry desert or semi-arid regions, such as in the southwestern United States or northern Mexico. It derives its characteristics from being a continental (c) air mass and originating from the tropics (T).
The air mass that forms near the Tropic of Cancer or the Tropic of Capricorn is warm and moist. These air masses are formed over tropical regions where the air is heated by the sun, leading to warm temperatures and high humidity.
A hot air mass that forms over land is called a continental air mass.