Atmospheric instability

Atmospheric instability is a condition where the atmosphere is generally considered to be unstable and as a result the weather is subject to a high degree of variability through distance and time [ [http://www.ace.mmu.ac.uk/eae/Weather/Older/Stability_of_Air.html Stability of Air ] ] . Atmospheric stability is a measure of the atmosphere's tendency to encourage or deter vertical motion. In unstable conditions, a lifted parcel of air will be warmer than the surrounding air at altitude. Because it is warmer, it is less dense and is prone to further ascent. In meteorology, instability is described by a lifted index and a K-index.

There are two primary forms of atmospheric instability [ [http://www.piercecollege.edu/offices/weather/stability.html Explanation of Atmospheric Stability/Instability - by Steve W. Woodruff ] ] :

* Convective Instability

* Dynamic Instability

Under convective instability thermal mixing through convection in the form of warm air rising leads to the development of clouds and possibly precipitation or convective storms.

Dynamic instability is produced through the horizontal movement of air and the physical forces it is subjected to such as the Coriolis force and pressure gradient force. Dynamic lifting and mixing produces cloud, precipitation and storms often on a synoptic scale.

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