Processes That Change the Potential Instability

Typical scenario to increase potential instability over the southern plains

In general, those processes that increase the moisture content of the lower levels and/or decrease the moisture content at higher levels tend to create or increase potential instability.

This graphic shows an example with the advection of warm, moist air from the Gulf of Mexico at low levels and advection of drier air in southwesterly flow aloft. These conditions substantially increase potential instability leading to initiation of severe thunderstorms over the Southern Plains, especially in the spring season.

It is important to note that all the previously discussed effects that change the lapse rate can indirectly change the vertical distribution of potential stability and instability at a given location.

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