Split Front - Cloud Structure In Satellite Images

by ZAMG and FMI


Definition: A Split Front is accompanied by a cyclonically curved cloud band, which, contrary to a classical Cold Front (see Cold Front ), contains a distinct double banded structure with cold cloud top temperatures at the leading edge and warmer cloud top temperatures at the rear edge: Note: In literature (especially US) the name Split front has been used in relation to an upper level Cold Front. This is comparable to "Frontal delay by mountains" and "Decoupling of cloud layers at different heights" in this manual (see Orographic Effects on Frontal Cloud ).
30 August 2005/06.00 UTC - Meteosat 8 IR 10.8 image
30 August 2005/06.00 UTC - Meteosat 8 WV 6.2 image
30 August 2005/06.00 UTC - Meteosat 8 VIS 0.8 image
The leading high cloud band can be observed in the IR and WV images over the Atlantic from 30W/45N to 18W/57N; in contrast to the schematics this is a case where the leading cloud band consists predominantly of high level clouds.
The long rear cloud band, with warm tops, can be seen from 32W/46N to 20W/57N. The jet axis is indicated in the WV image by the two dark lines behind the front. In this case the jet axis is almost perpendicular to the front. The convective cloudiness in the rear cloud band on the cyclonic side of the jet or within the jet is not very striking (but it is there!), but there is dry sinking air above the rear cloud band on the anticyclonic side of the jet.
Surface and upper level fronts are in accordance with the schematic, as shown in the vertical cross section described in more detail later on.

Menu Of Split Front
Meteorological Physical Background