Vertical draft
（重定向自Downdraft）
- For the band, see Air Pocket (band)
An updraft is a small‐scale current of rising air, often within a cloud. One of two forces causes the air to move. Localized regions of warm or cool air will exhibit vertical movement. A mass of warm air will typically be less dense than the surrounding region, and so will rise until it reaches air that is either warmer or less dense than itself. The converse will occur for a mass of cool air, and is known as subsidence. This movement of large volumes of air, especially when regions of hot, wet air rise, can create large clouds, and is the main cause of thunderstorms. Drafts can also be created by low or high pressure regions. A low pressure region will attract air from the surrounding area, which will move towards the center and then rise, creating an updraft. A high pressure region will then attract air from the surrounding area, which will move towards the center and sink, creating a downdraft.