SPLIT FRONT - CLOUD STRUCTURE IN SATELLITE IMAGES

by ZAMG


A Split Front is accompanied by a cyclonically curved cloud band, which in contrary to a classical Cold Front (see Cold Front) contains a distinct double banded structure with cold cloud top temperatures at the leading and warm cloud top temperatures at the rear edge:
02 September 1995/12.00 UTC - Meteosat IR image; position of vertical cross section indicated
02 September 1995/12.00 UTC - Meteosat WV image
02 September 1995/12.00 UTC - Meteosat VIS image
The leading high cloud band can be observed in the IR and WV images from the North Sea across the Netherlands and Belgium to France (approximately 46N/00E); in contrast to the schematics this is a case and/or a stage of development where the leading cloud band consists predominantly of high cloudiness.
The rear cloud band with warm tops can be seen best over France and the English Channel.
The jet axis is indicated in the WV image by the dark area reaching from the Atlantic (approximately 56N/18W) across Ireland to Cornwall as well as by the cloud fibres across Normandy.
According to this, two phenomena described before can be observed: the development of convective cloudiness in the rear cloud band on the cyclonic side of the jet (south-east England), and the dry sinking air above the rear cloud band on the anticyclonic side of the jet (from the Bay of Biscay to France, approximately 47N/06W to approximately 48N/04E).
Surface and upper level front are in accordance with the schematic presentation, as can be seen in the vertical cross section described in more detail later on: a surface cold front is identified in the area of the English Channel and an upper level Cold Front over France at about 48N/03E.

SUB-MENU OF SPLIT FRONT
METEOROLOGICAL PHYSICAL BACKGROUND