The condition of the atmosphere at a certain time and place.

Any form of water that falls to the Earth's surface from the clouds.

A collection of small water droplets or ice crystals suspended in the air, which forms when the air is cooled and condensation occurs.

A large body of air where temperature and moisture content are constant throughout.

The amount of water vapor in the air

The change of state from a gas to a liquid.

The boundary between air masses of different densities and usually different temperatures.

A usually brief, heavy storm that consists of rain, strong winds, lightning, and thunder.

The temperature at which a gas condenses into a liquid.

Occurs when water vapor cools and changes from a gas t a liquid. Clouds form by this process.

Occurs when liquid water changes into water vapor, which is a gas.

Occurs when rain, sleet or hail falls from the clouds on to Earth's surface.

Puffy white clouds that tend to have flat bottoms.

Thin feathery white clouds found at high altitudes.

Clouds that form layers.

This air mass type forms over water; wet.

This air mass type forms over land; dry.

This air mass type forms over polar regions; cold.

This air mass type forms over the tropics; warm.