Images and combinations which are helpful in diagnosis of convective events are:
Airmass RGB, as defined by EUMETSAT is: "an RGB composite based upon data from infrared and water vapour channels from Meteosat Second Generation. It is designed and tuned to monitor the evolution of cyclones, in particular rapid cyclogenesis, jet streaks and PV (potential vorticity) anomalies. Due to the incorporation of the water vapour and ozone channels, its usage at high satellite viewing angles is limited. The Airmass RGB is composed from data from a combination of the SEVIRI WV6.2, WV7.3, IR9.7 and IR10.8 channels."
In this chapter the cloud configurations seen in the IR10.8 image are enhanced by using colours for temperature intervals (from 240 to 200 K) in a way that also overshooting tops are identified. The theory of this can be found in the articles by Martin Setvak , Atmos. Res. 83 (2007).
This RGB composite is made by combining WV6.2 - WV7.3 BTD on red, IR3.9 - IR10.8 BTD on green and the diference of NIR1.6 - VIS0.6 reflectance on blue. It gives the information on deep precipitating clouds with special emphasis on Cb clouds with strong updrafts. The later were not very recognizable in this event.
The most important information about the convective development in this case was shown by the colour enhanced IR images, since the "cold ring" shape was seen in the hours from 6:30 to 7:30 UTC, indicating that cloud tops reached the tropopause level. The lightning data are also showing that very intensive processes were persisting and renewing over the same small areas. In this case Convective Storm RGB combination was not very indicative, since the light yellow colour, a signal for severity of the storm, was not present. The reason was probably that the small ice particles were not coming to the very top of the clouds.