Lifted index

The lifted index (LI) is the temperature difference between an air parcel lifted adiabatically and the temperature of the environment at a pressure height in the atmosphere, usually 500 hPa (mb). When the value is positive the atmosphere (at the respective height) is stable and when the value is negative, the atmosphere is unstable. LI can be used in thunderstorm forecasting, however, convective available potential energy (CAPE) is a better measure of instability and is what is used primarily.

See also

• Convective instability
• Atmospheric thermodynamics