A Skew-T/Log P is an atmospheric sounding that is used by meteorologists to assess the stability (state) of the atmosphere. It tells meteorologists the environmental lapse rate, the dry and moist adiabatic rates(DALR & MALR). From this, meteorologists can evaluate how a parcel (theoretical bubble of air) interacts with its environment. This is crucial to rain formation, as clouds form in unstable conditions (when either the DALR & MALR are less than the ELP, which is absolute instability, or when the ELP lies between the DALR & MALR). Also, parameters such as Convective Available Potential Energy (CAPE), the Lifted Index, the K Index, and many other measurements derive from the Skew-T. These may be used to compose forecasts.