Determining Stability » Potential Instability Determination of Potential Instability
In the ear1y 1930s, Rossby introduced a criterion for the instability or stability of a layer resulting when it is lifted as a whole, as at a front or mountain. This criterion came to be known as "potential instability," also known as "convective instability." To determine potential instability, one compares the lapse rate of the wet-bulb temperature to the moist (saturation) adiabatic lapse rate:
- Layers in which the wet-bulb lapse rate is greater than moist (saturation) adiabatic are potentially unstable.
- Layers in which the wet-bulb lapse rate is less than moist (saturation) adiabatic are potentially stable.