Cold Front
Cold Fronts are accompanied by synoptic scale multilayered cloud bands.
Fronts generally form within a baroclinic boundary between cold and warm air masses. The main physical process for the development of Cold Fronts is the movement of the cold air against warm air. The warm air ascends along the boundary while the cold air sinks below it. If there is enough humidity, the upward motion leads to condensation and to the development of clouds and precipitation. Cold Fronts can be devided into two types: Ana and Kata Cold Fronts. The main feature which separates the different types of Cold Front is the orientation of the jet relative to the front in the middle and upper levels of the troposphere. It is generally considered that a Kata Cold Front evolves from an Ana Cold Front. As baroclinic disturbances often develop over the Atlantic, the newly developed Ana Fronts can mainly be found there, whereas older, continental fronts are mostly Kata type. Another reason for the spatial differences might be that the lower parts of the front are decelerated due to the friction of the continent, while the upper parts continue with higher speed.