The boundary between two different air masses where warm air pushes cold air away to bring warmer weather.
Water Vapour::
Water in its gaseous form. One of the most important constituents of the atmosphere and also the most variable in space and time. Caused by evaporation at the Earth's surface the concentration of water vapour tends to decrease fairly steadily with height.
Wave Cyclone:
A storm or low-pressure centre that moves along a front.
Weather:
The changing atmospheric conditions at a place or time, including temperature, humidity, wind, cloud and precipitation as they affect man.
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Warm Front: