Convection is driven by buoyancy forces that cause parcels of air to rise or sink relative to their environment. Buoyancy is determined by the difference in density between a parcel of air and its surroundings, with warmer less dense parcels tending to rise and cooler denser parcels tending to sink under the influence of gravity. The amount of potential energy a parcel of air possesses as it rises is known as convective available potential energy (CAPE), which is an important parameter for forecasting thunderstorm development and intensity.
