EUMeTrain: Case Study on severe convection over Central and Eastern Europe


Jarno Schipper
Veronika Zwatz-Meise


This case study will be about the severe convective development in Central and Southeastern Europe. In the pictures below both of these convective areas are pictured.

Meteosat 8 RGB (HRVIS; HRVIS; IR10.8)
29th May 2005: 1200UTC
Meteosat 8 RGB (HRVIS; HRVIS; IR10.8)
30th May 2005: 1500UTC

The left picture shows the convective area which is addressed in the first part of this case study. Numerous cells are covering the coastal regions of Greece, Turkey, Albania, Italy and Bulgaria. Reports of thunderstorms, rain in association with hail were observed on this day. In the right picture three seperated mesoscalic cloud systems (MCS) are seen covering Austria, Czech Republic and the Southwestern part of Poland. The shadow of these cells on the earth surface can clearly be recognised. At a later stage these seperate cells merge and supercell storms are observed. Numerous reports of hail were reported associated to this event.

The rate in which the convection developed over the Czech Republic is pictured perfectly in the webcam movie shot over Prague in the early afternoon of 30 May. In shy over 45 minute explosive development is witnessed. The animation was provided by the courtesy of Martin Setvak (CHMI).

The aim of this case study is to:
To be able to follow the case study from the beginning it is preferable to study the chapters dealing with convection from the "Manual of Satellite Meteorology", and the powerpoints dealing with hazardous small scale weather from the "MSG Interpretation Guide" .

In the case study two types of convective development are observed and addressed. At the 30th of May a broad N-S oriented frontal zone is covering Western Europe. On the leading side of this front several convective cells emerge. It is at this position that in WV imagery a dry intrusion is observed. Also in Greece and Turkey several cells emerge on the boundary of low and high pixelvalues of the WV imagery. The convective development in Greece and Turkey can be characterised as fair weather convection. This boundary represents the transition between relatively humid and dry air at levels above 600 hPa.

In this case study it will be seen that the convective developments have similarities and differences. With use of several Meteosat 8 satellite images and composites and with the use of basic and derived numerical parameters these differences and similarities will be worked out.