The cold front is how the warm front, a weather phenomenon associated with a low pressure area. The cold air moves here in the direction of the hot air. Due to the cold front arises in the normal case, a cooling at all heights of the air layers. But it also differs fronts, where it occurs only in higher layers of the atmosphere to cool. This is called an altitude cold front. Furthermore, it may happen that in winter, the ground- cooled- air mass is replaced by milder maritime cold air. Thus, it is even warmer in the near-surface layers. This is known as a masked cold front.
Further to the cold front is different in accordance with the flow characteristics of cold air towards the hot air. When the cold front of the first kind ( Anafront ) pushes the cold air under the warm air and the cold front of the second kind ( Katafront ) pushes the cold air over the warm air; further explanation see below.
Cold fronts are characterized by increased vertical air movements. The resulting convective clouds occur frequently leads to enhanced showery precipitation or thunderstorms. The arrival of a stronger cold front can often be well observed: Pretty Tough, slightly chilled wind, cumulus clouds (possibly quite a few cumulonimbus clouds) announce it. The temperature drops when passing by several degrees, it may even happen that after a beautiful spring day at 16 ° C the next day after passage of the cold front snow.
On the back of the cold front (cold sector) the atmosphere is usually layered unstable. Together with the still wet from the rain under the floor leads the sunlight to cumulus clouds and showers, the weather back as mentioned. Furthermore, the air pressure increases again after passage of the front. Because the air is absolutely and relatively less humid than before the rainfall, the air, the view is clear and good. Has the cold front caught up with the advancing warm front, an occlusion is formed.
In a weather map cold fronts are indicated by blue triangles pointing in the direction of pull.
According to the classical theory of cold air gets under warm air, convergence occurs at the air-mass limit. Here, the warm, moist air is forced to rise. The result is cloud formation and precipitation behind the cold front.
In the representation of the cold air from right thrust; Pressure and temperature curves, in contrast, set in mirror image.
In Katakaltfront the cold air via the hot air device. The rising of the warm air is prevented by the fall of the dry air. Thus, even the cloud development, which takes place in front of the cold front, kept small.