Depressions are parts of the weather phenomenon which are also referred to as “mid-latitude cyclones” or “lows” . They are low pressure belts that occur between latitudes of 30° and 60°. The formation of depressions takes place when warm air from sub-tropical regions mix with cold air of the polar areas. The mid-Atlantic is a popular meeting point of the cold air of the Polar Regions and the warmer air of the sub-tropical regions. Depressions generally have distinct cold and warm fronts when warm air forcibly rises over cold air.

Different stages of Depressions are :

•  Origin : It begins its life in the form of a wave by 'buckling' over a front. The southern part of the front has warm air while the north remains cold.

•  Maturity : After the development of the depression , the pressure goes down around it. The weather chart records this as a group of tight isobars. Due to this the winds get stronger and there is torrential rain.

•  Occlusion : This happens when a cold air undercuts warm air starting from the center of the depression. The rainfall becomes more intermittent now.

•  Death : This takes place when the fronts die leaving only cold air and pushing the warm away from the land. The temperatures on either side of the front get equalized.

Depression and Weather :

Depressions are of different types; therefore, the kind of weather that is associated with each depression is separate. A classic depression is characterized by a weather which follows certain general rules.

Various Types of Depressions :

•  Polar Lows

•  Thundery Lows

•  Lee Lows

Depressions are areas having low pressure but they can also be referred as cyclones.