Formation of cumulus congestus clouds as the centre of a weak low pressure system passed over the Maltese Islands. It was preceded by isolated thunderstorms before the winds veered easterly. The first thumbnail is another shot of the cumulus clouds that formed which correspond with the visible satellite image on the third thumbnail and in turn corresponding with the SLP chart at around midnight on the fourth thumbnail as a cold drop moved towards the Maltese Islands. The weather sounding on the second thumbnail proved that there was little instability for the photographed clouds to become cumulonimbus clouds.