Far-away thunderstorm cloud as viewed from Malta due to diurnally-driven convection clouds over nearby Sicily (heating of landmass during the day forming sea-breezes which given the right meteorological conditions interact together forcing the air to rise upwards hence forming huge clouds). The satellite image proves this. On the other hand, only a few cumulus clouds formed over inland Malta. On the surface pressure chart, one can notice a surface high pressure system over the British Isles which during Winter normally drags unstable air masses towards the Central Mediterranean from the NE.