LCL-LFC Relative Humidity (%)

This is the mean relative humidity in the layer between the LCL (Lifting Condensation Level) and the LFC (Level of Free Convection). Near saturation (RH=100%), from the LCL to the LFC, suggests that the LFC is near the LCL. When this occurs, a parcel experiencing forced ascent above the LCL may not be diluted with dry environmental air prior to reaching the LFC.

The height difference between the LCL and the LFC is important when determining convection initiation. The smaller the difference between the LCL and the LFC, the more likely deep convection becomes. The LCL-LFC difference is similar to CIN (convective inhibition).