Vertical Cross Section

Isentropes
In the 30 hours which have passed after the first Vertical Cross Section was made, a synoptic scale cloud spiral has developed which extends from Finland to Poland. At this time a double structure in the frontal cloud band exists and could be explained with help of the WV images by dry air overflowing the cloud band in high levels. The line of the Vertical Cross section goes through a more northern part of the cloud band.

The VCS was laid from position A to B.

Temperature Advection
The Isentropes show a configuration which is very typical for an occlusion front: a well developed isentropic trough. The western baroclinic boundary is from about 450 hPa downward. This configuration contradicts somehow to the history of the development of the “growing cloud spiral” as this part of the cloud band has developed and became enhanced only after the existence of a distinct cloud spiral.

TA is also typical for an occlusion stage. There is intensive WA in and in front of the center of the isntropic trough and CA in high levels above. Only above the tropopause intensive WA can be seen again.

Convergence
Both baroclinic boundaries at the border of the isentropic trough but especially the western one are accompanied by maxima of convergence. Which indicates the weather activity of the cloud band.

Temperature Advection	Convergence	Vertical Motion (omega)
Vorticity Advection	PV

Vertical Cross Section Cloudspiral: 2nd March 2004:12UTC