Formation of stratocumulus cloud with clear mamma-like features on its upper section on the left hand side of the photo and with a more cumulus-like feature towards the right. Specifically, such cloud is known as `Stratocumulus Cumulogenitus` but I do not know whether such cloud is specifically a sub-species. Scientists still do not understand the exact mechanisms behind such cloud formation but from this photo it seems that the stabilisation of the cloud from stratocumulus perlucidus just above it may have played a key role. In fact, the first thumbnail shows a specific photo of stratocumulus perlucidus that formed on this day. The cloud species have formed due to the weak section of an upper-level trough (second thumbnail) affecting the Maltese Islands. The airmass was somewhat unstable only in the very low layers of the atmosphere with stability higher up at altitude. Such air profile is very conducive for the formation of stratocumulus.