the continued rising of an air mass as it is warmer than the surrounding, or environmental, air. This is especially common after the rising mass has passed the dew point and so cools at the saturated adiabatic lapse rate as the release of latent heat keeps the mass warmer. The term instability is used as the continued rising leads to further opportunity for condensation and thus the build up of large, dense storm clouds.
Geography Dictionary & Glossary for Students \\ ITS Tutorial School (ITS) - Hong Kong.