Parameter

13 February 2005, 12 UTC

The main system at this point in time was a deep low over Denmark, North Germany and Baltic Sea.

At this point there are still no clouds connected to the development in the Genoa Bay, but the through in the AT1000 height field is clearly visible.

Another feature that can already be notice in this first time-step is the strong gradient of the isohypses across the whole Western Europe, caused by the difference in pressure between the low over Northern Europe and a large high over the Atlantic. The gradient is the strongest over the UK and Northwest France, but also in the Genoa Bay.

13 February 2005, 18 UTC

There is now a closed low at 1000 hPa level over North Italy.

14 February 2005, 00 UTC

The cold air coming directly from the north down to France, the low over North Italy spreading and the gradient of the isohypses accross the South France becomes stronger.

14 February 2005, 06 UTC

At this point the spiral structure of the cloud band becames visible. The low over Italy moved southwards creating a high pressure gradient zone between the Baleares and Sardinia and over South France.

Mean surface wind speed at that time was reaching 54 knots at South France, mostly along the coast.

14 February 2005, 12 UTC

The low moved more to the south and the pressure gradient zone becomes much stronger. Parallel to the isohypses there are cloud streets (which can be much better seen on the HRV images) indicates flow of the cold air.

The mean surface wind speed at that time was not the strongest, but wind gusts in South France was reaching 84 knots. The very strong gusts was also reported at the sea between Sardinia and Baleares where the cruise ship "Voyager" got into difficulties.

14 February 2005, 18 UTC

Cloud spiral connecting with the low moved to the south.

15 February 2005, 00 UTC

The low becames deeper. The pressure field gradient becames stronger also at the Adriatic coast.

15 February 2005, 06 UTC

The big part of the Mediterranean and Central Europe is under the influence of cyclone which center is over South Italy.

At the front side of the cyclone the cloudiness was connected with pecipitation, mostly snow, but on the back side, in the Mediterranean cloud structure was connected with showers and thunderstorms.

15 February 2005, 12 UTC

At this time step the low is spreading. At the upper level the big cyclone with the center over Mediterranean and Central Europe is also present:

see image

15 February 2005, 18 UTC

Inside the extensive low cloud spiral is present over Italy.

16 February 2005, 00 UTC

In cloud structure the strong convection can be seen in the Genoa Bay. The trough over Austria and Slovenia indicated a new developement of the low.

16 February 2005, 06 UTC

At this time step the cyclone is weaking, but there is still a sign of convection in the Mediterranean. Another weak low now is formed over Hungary.

16 February 2005, 12 UTC

The low over Mediterranean was stationary, and in the upper level was still deep cyclone.

Geopotential Height 1000 hPa