Conditionally Unstable - 1
In this plot, if a parcel of air with temperature T and dewpoint Td is lifted, it will move along the dry adiabat until it reaches saturation at Point T1. If the parcel is lifted further, it will move along the moist adiabat to Point T3. Prior to reaching Point T2, the air is colder and denser than its surroundings, and in the area T-T1-T2, may be considered to be stable. However after passing Point T2, the air is always warmer and less dense than its surrounding and is therefore unstable. We refer to this point (T2) as the level of free convection (LFC). The air is said to be conditionally unstable. "Conditional" means that the lifted parcel is stable if unsaturated and unstable (above the LFC) if saturated. In the case of downward displacement, the temperature of both initially saturated and unsaturated parcels would follow the dry adiabat.