| a transition zone between a mass of warm air and the colder air it is replacing. |
| warm front n. A front along which an advancing mass of warm air rises over a mass of cold air. |
| warm front
The forward edge of an advancing mass of warm air that rises over and replaces a retreating mass of cooler air. As it rises, the warm air cools and the water vapor in it condenses, usually forming steady rain, sleet, or snow. On a weather map, a warm front is depicted as a red line with half circles whose curved sides point in the direction in which the warm air is moving. Compare cold front, occluded front. See illustration at front. |