A boundary between two air masses (one cold and the other warm) moving so that the warmer air replaces the colder air.
A boundary between two air masses (one cold and the other warm) moving so that the colder air replaces the warmer air.
high pressure system
A whirling mass of cool, dry air. Because cool air is heavy and denser than warm air, it sinks. This type of pressure brings fair weather, sunny skies, light winds, and stable weather.
low pressure system
A whirling mass of warm, moist air. Because warm air is lighter and less dense than cool air, it rises, and then cooler air flows in underneath. This type of pressure systems bring storms, strong winds, and changing, unstable weather.
The weight of air pressing down on earth. It can change from place to place, and this causes air to move, flowing from areas of high pressure toward areas of low pressure. It's the same as barometric pressure.
A boundary between two air masses, resulting in stormy weather. A front is usually a line of separation between warm and cold air masses.
the measure of how tightly packed the matter in an object is (hot air & low pressure = less dense, cool air & high pressure = more dense)