In meteorology, convective instability or stability of an air mass refers to its ability to resist vertical motion.Instability can lead to significant turbulence, extensive vertical clouds, and severe weather such as thunderstorms.The ambient or environmental lapse rate is the temperature change in the (non-displaced) air per vertical distance.Cool, dry air is very stable and resists vertical movement, which leads to good and generally clear weather.It was first introduced as a simple but useful measure of the strength of the inversion that caps the planetary boundary layer on earth, and also indicates the level of convective stability of an air column at a given location.[3] Regions with negative LTS have a larger potential temperature on the surface than in the mid-troposphere, which makes the air column unstable and encourages convection.There is a major limitation of this measure of stability however, which is that it does not take the thermodynamic properties (saturation mixing ratio and therefore the shape of adiabats in the lower troposphere) of the air into account.A more refined measure of stability has since been developed, named the estimated inversion strength, which pays closer attention to the thermodynamic properties of the air in the lower troposphere.