Early morning formation of a large cumulonimbus cloud caused due to an upper-level trough around Malta and surface low pressure over the entire Mediterranean. This low was on a slow weakening trend but still being maintained by the warmer sea surface temperature. Weak winds and instability at all atmospheric levels also aided to this cloud development and perhaps it led for its anvil to be evenly spread. The first thumbnail shows another Cb incus but this time a bit sheared due to some wind.