LCL, LFC, & EL

Lifting Condensation Level (LCL)

The level at which a parcel becomes saturated. It is a reasonable estimate of cloud base height when parcels experience forced ascent.

In the figure to the right, the LCL occurs at 2000m.

Image Description: Lifting Condensation Level (LCL) X-Y graph with altitude in meters on the y-axis and temperature in Celsius on the x-axis. The dry adiabatic lapse rate is shown as decreasing by 9.8 Celsius per 1,000 meters. The level of condensation occurs at 2,000 meters, when the parcel becomes saturated, and a cloud is formed. Once the parcel is saturated, the moist adiabatic lapse rate of 6 Celsius per 1,000 meters is used.

Level of Free Convection (LFC)

The level at which a lifted parcel becomes warmer than its environment and begins a free acceleration upward to the equilibrium level.

Equilibrium Level (EL)

The level at which a lifted parcel becomes cooler than the environmental temperature and is no longer buoyant (i.e., no longer unstable). The EL is used primarily to estimate the height of a thunderstorm anvil.

Convective Available Potential Energy (CAPE)

The area between the LFC and the EL represents the fuel available for a developing thunderstorm.

Learn more here!

Image Description: Decoding more Skew-T Variables Skew-T/Log-P diagram The parcel air temperature is seen in dark blue, and the environmental temperature is seen in black. The LCL is marked where the parcel becomes saturated. The LFC is marked when the parcel becomes warmer than the environment (the blue line is to the right of the black line. The area filled in green represents positive CAPE values, which is the convective available potential energy, which fuels developing thunderstorms. The EL is marked when the parcel becomes cooler than the environmental temperature.

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