Formation of cumulonimbus clouds with an over-shooting top due to instability instigated by an upper cold pool of air in the vicinity of the Maltese Islands. On the surface weather chart a line of bad weather was present over the Maltese Islands. The weather sounding showed steady decrease in temperature with height and moisture extending up to 500mb height. The other 2 pics show the widespread initiation of cumulus congestus and a cumulus cloud with a flat hood respectively. The latter photo indicates that the cloud has reached a more stable layer within the atmosphere or that the air bubble within it was not enough buoyant (ie: not able to rise as much). The weather charts can be found here.