An outflow boundary is a storm-scale or mesoscale boundary separating thunderstorm-cooled air (outflow) from the surrounding air; similar in effect to a cold front, with passage marked by a wind shift and usually a drop in temperature. Outflow boundaries may persist for 24 hours or more after the thunderstorms that generated them dissipate, and may travel hundreds of miles from their area of origin. New thunderstorms often develop along outflow boundaries, especially near the point of intersection with another boundary (cold front, dry line, another outflow boundary, etc.; see triple point). The term mesoscale is a size scale referring to weather systems smaller than synoptic scale systems but larger than storm-scale systems. ... A rolling thundercloud over Enschede, The Netherlands. ... This is a disambiguation page — a navigational aid which lists other pages that might otherwise share the same title. ... In meteorology, a weather front is a boundary between two air masses with differing characteristics (e. ... Wind is the quasi-horizontal movement of air (as opposed to an air current) caused by a horizontal pressure gradient force. ... Temperature is the physical property of a system which underlies the common notions of hot and cold; the material with the higher temperature is said to be hotter. ... In meteorology, a weather front is a boundary between two air masses with differing characteristics (e. ... In meteorology, a weather front is a boundary between two air masses with differing characteristics (e. ... In physics, the triple point of a substance is the temperature and pressure at which three phases (gas, liquid, and solid) of that substance may coexist in thermodynamic equilibrium. ...