Convective storm with marked gust front over Darmstadt in June 2005.
09 October 2023
29 June 2005
By Jochen Kerkmann and Gordon Bridge (EUMETSAT)
On 29 June 2005 a line of convective storms crossed The Netherlands and Germany causing widespread wind and rain damage. The convective storms can be seen on the HRV image (Figure 1) as the highly reflective clouds over western Germany with a V-type storm on the southern edge (see image interpretation below the image).
The latter storm reached Darmstadt around 19:00 UTC where it caused strong winds and one hour of heavy rain (in total around 50mm of rain). The image below the satellite images shows the arrival of the gust front (convective outflow boundary) in Darmstadt as observed from the ground. It shows the typical roll cloud (or shelf cloud), which marks the limit between the warmer pre-storm air and the cooler air produced by the outflow of the storm.
Concerning the RGB composite used to monitor severe convective storms (Figure 2), the storm over Darmstadt, although quite severe, did not appear with a yellow colour (indicating small ice particles). In fact, small ice particles at the top of convective clouds (especially in the early stage of development) are a typical sign of strong updrafts/downdrafts.
However, not all severe convective storms contain small ice particles, other features, like storm top temperature, storm texture, storm growth and storm movement are also very important for the interpretation of the severity of a convective storm.
Absolute topography 300 hPa (29 June 2005, 12:00 UTC, source: DWD)
Relative topography 500/1000 hPa (29 June 2005, 12:00 UTC, source: DWD)
Radiosounding of Stuttgart (29 June 2005, 12:00 UTC, source: DWD)
Weather radar image (29 June 2005, 19:00 UTC, source: DWD)
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