30th July 2005: 06UTC
With help of the modelfields of the LAM model Aladin the divergence/convergence at 700 hPa is pictured. Striking at this instance is the region with convergence over the cold front explaining the existance of only low cloudiness. Ahead of this front already outflow and divergence is observed in the area later marked as prefrontal convergence.
30th July 2005: 12UTC
Six hours later. The cold frontal part is still characterised by convergence and subsidence. Ahead of the cold front the prefrontal convergence line can already be observed in the model fields. A line with divergence can be seen stretching from Northern Italy over Slovakia into Poland and further north towards the Baltic States.
30th July 2005: 18UTC
The cold front has enhanced over the past 6 hours and shows already signs of convection. It is still superimposed by convergence aloft. Ahead of the front where the prefrontal convergence line has formed several regions with divergence, indicating the outflow, are still observed.
31st July 2005: 00UTC
By this time the prefrontal convergence line and the convective cells embedded into the cold front have merged forming a large MCS over Central Europe. The cells are all characterised by divergence at 700 hPa indicating the outflow aloft at these regions.
31st July 2005: 06UTC
Last image in this series. By this time the convection has mostly died out over night. Still up north some isolated MCS is observed, characterised by divergence. The cold front which lies over Austria, Bavaria and the Czech Republic consists of merely low clouds and which show maxima in convergence aloft indicative for subsidence and the decaying level of convection.
