Quizlet Fronts + Masses

Occluded Fronts

The most complex weather situation occurs at an occluded front, where a warm air mass is caught between two cooler air masses. The denser cool air masses move underneath the less dense warm air mass and push the warm air upward. the two cooler air masses meet in the middle and may mix. The temperature near ground becomes cooler. The warm air mass is cut off or occluded from the ground. AS the warm air cools and its water vapor condenses the wether may turn cloudy and rain or snow may fall.

Stationary Fronts

Stationary Fronts is when cold and warm air masses meet, but neither one can move the other. The two air masses face each other in a standoff. Where the warm and cool air meet, water vapor in the warm air condenses into rain, snow, fog, or clouds. If a stationary front remains stalled over an area, it may bring many days of clouds and precipitation.

Warm Fronts

Clouds and precipitation also accompany warm fronts. At a warm front, a fast-moving warm air mass overtakes a slowly moving cold air mass. Since the warm air is less dense then cold it move over the cold air. If warm air is dry it scattered clouds form.

Cold Fronts

Cold fronts is more dense than warm air that intend to rise but cold intends to sink in. When a rapidly moving cold air mass runs into a slowly moving warm air mass, the denser cold air slides under the lighter warm air. The warm air is pushed upward along the leading edge of the colder air. As the warm air rises, it expands and cools. Remember that warm air can hold more water vapor than cool air. The rising air soon reacher the dew point, the temperature at which the water vapor in the air condenses into droplets of liquid water if forms tiny ice crystals. Cloud form. If there is a lot of water vapor in the warm air, heavy rain or snow may fall. If the warm air mass contains only a little water vapor, then the cold front may be accompanied by only cloudy skies. Since cold fronts tend to move quickly, they can cause abrupt weather changes, including thunderstorms, After a cold front passes through an area, colder, drier air moves in, often bringing clear skies, a shift in wind, and lower temperatures.