The first major outbreak of thunderstorms in Central Europe in 2009 occurred on the 25th of May. During this day large parts of western and central Europe (France, Belgium, The Netherlands, Luxembourg, Germany, Switzerland, Northern Italy, Austria, the Czech Republic, Hungary, Slovenia and North-Western Poland) were affected by some very severe convective events (isolated multicells, supercells, and mesoscale convective systems). All participants of the CWG having interesting material related to this case are strongly invited to upload and discuss in this page!
The day was characterised by a band of unstable airmass in the southern part of Central Europe, reaching from France via Southern Germany and Austria down to the Eastern Adriatic coast, while much more stable conditions are prevailing to the north and the south of this band.
This unstable airmass is equally well visible in the K-Index, where values exceed 30 °C, in the Lifted Index, where values at around -6 K, in some areas values even below -8 K were reached, and in the Total Precipitable Water (TPW) content, which shows the associated humidity of around 30 mm.
The Lifted Index is by definition driven by near surface heating and thus shows the expected diurnal cycle, while both the K-Index and the TPW show much less temporal changes.
It is well visible that the afternoon convective activity is pretty much confined to the area of this initial instability, with the exception of Italy, where orographic effects may both enhance the convective initiation and somewhat mask air instability due to the definition of the respective indices.
24-hour loop of the K-Index: http://convection.satreponline.org/showcase/gii/kindex.html
24-hour loop of the Lifted Index: http://convection.satreponline.org/showcase/gii/li.html
24-hour loop of Total Precipitable Water: http://convection.satreponline.org/showcase/gii/tpw.html
Please follow the link to the SATCAST Case Study 25/05/2009
Through the link below you can see how the NWCSAF CRR product showed this event:
You may place here your text and images on sandwich products, cold ring shaped storm and else related to the mature phase of our guys.