Warm Conveyor Belt
Middle and high level cloud in a rising warm, moist air stream relative to its system velocity.
The Warm Conveyor Belt is a rising relative stream transporting warm wet air from south-east to northern directions. Warm Conveyor Belts are directly involved in the frontal processes, but typical cloud configurations can also be observed separately from the frontal cloudiness. Different states of the atmosphere are responsible for these two types: 1.) The cloudiness of a front is developed within two relative streams: the Warm Conveyor Belt and a less wet relative stream from the trough area behind. the Warm Conveyor Belt is connected at least with the leading part of the cloudiness, therefore the relative stream lines approach or even overrun the surface front. 2.) In the case of separated Warm Conveyor Belt cloudiness the relative stream lines are in front of the frontal cloud band and the relative stream from behind crosses the frontal line in a forward direction, consequently approaching the stream lines of the Warm Conveyor Belt. A survey by ZAMG has shown that over the past two years over 57% of the Warm Conveyor Belts that occurred happened over North-Africa and the Mediterranean and could be subscribed to the more isolated and separated type of Warm Conveyor Belt. Of the 467 cases examined less than 70 (15%) occurred over western, northern or eastern Europe and were mostly connected to a frontal system.