The VCS is drawn through a large zone of cloudiness of the cold front and the convective cloudiness ahead of the front.
The lower troposphere is unstable, especially the coast line of the Black Sea.
The VCS was laid from position A to B.
Relative humidity
Relative humidity cross-section confirms the situation
depicted by the satellite image. The air is very moist almost through the whole region. The cold front cloudiness
can be recognized
as the area of high relative humidity values extending from 750 up to 400 hPa. The high values from the low level up to 500 hPa
corresponds to the position of the big convective cell at the leading edge of the frontal cloudiness.
Sinking dry air at the rear of the cold front and ahead of the cloud zone is seen.
The VCS was laid from position A to B.
Temperature Advection
The pronounced cold advection in the
shallow layer of the lower troposphere is still present. The
cold advection aloft is much weaker.
The VCS was laid from position A to B.
Divergence/Convergence
At this stage of development of the most unstable part of the system is
located in eastern Turkey. It can be easily recognized by the
backward inclined maxima of convergence (thick lines)
over the Black Sea coast up to 700 hPa and further to
the west in the upper levels from 700 to 500 hPa.
The VCS was laid from position A to B.
Vertical Motion
The system has already started to disolve. That is confirmed by the
descending motion (positive values)
in lower troposphere. Ascending motion stil exist
in the upper troposphere, in
the area of well developed convective cells.
