An updraft or downdraft (air pocket)'s the vertical movement of air as a weather related phenomenon. Commonly, one of two forces causes the air to move. Localized regions of warm or cool air will exhibit vertical movement. A pocket of warm air will typically be less dense than the surrounding region, and so will rise until it reaches air that's either warmer or less dense than itself. The converse will occur for a mass of cool air, and's known as subsidence. This movement of large volumes of air… (More on Downdraft)