Saturated air can be unstable even though its potential temperature increases with height : if the warming due to condensation is enough that a parcel of saturated air which is displaced upward ( and would otherwise cool to below the ambient temperature ) ends up warmer ( lighter ) than the surrounding air, it will continue to rise.
32.
A gas in this context is referred to as saturated when the vapor pressure of water in the air is at the equilibrium vapor pressure for water vapor at the temperature of the gas and water vapor mixture; liquid water ( and ice, at the appropriate temperature ) will fail to lose mass through evaporation when exposed to saturated air.
