fronts

Contact surface between two air masses with different temperatures and pressure.

surface cold front

Front consisting of a cold air mass that touches the ground and displaces a warm air mass.

upper warm front

Front consisting of a warm air mass that does not touch the ground and slides over a colder air mass.

surface warm front

Front consisting of a warm air mass that touches the ground and displaces a cold air mass.

stationary front

Front that moves very slowly owing to the parallel movement of hot and cold air masses.

occluded front

A composite front that forms when a cold front overtakes a warm front, which it pushes to a higher altitude before joining another cold front.

upper cold front

Front of a cold air mass that does not touch the Earth’s surface and slides over a colder air mass.