An instrument that measures air pressure. The leading edge of a cold air mass that is moving. A process that releases heat which occurs when a gas becomes a liquid. Tiny objects in the atmosphere such as dust where condensation of water vapor into water droplets take place. Transfer of heat by molecular activity.
Heat always flows from hot to cold objects.
Movement in a fluid that results in the transport and mixing of that fluid. In weather, it is the upward motion that helps to produce clouds. An area of lower pressure dictated by stormy, unsettled weather. The temperature that air has to be cooled to for condensation to take place. It also represents a measurement of the amount of water vapor in the atmosphere.