Local cumulus cloud formation due to remnants of upper-level cold air over the Central Mediterranean. However, the main cause behind this cloud formation was that winds from 2 surface low pressure areas, one over NW Libya and another between Greece and Turkey, collided together over the eastern side of Malta as can be clearly seen in the nullschool wind map. Such wind collision forces the air to rise upwards to considerable altitudes given the right conditions. In this case, the general environment was only marginally unstable (with decreasing instability over the day) hence deep cumulonimbus clouds did not develop but still produced localized rain showers. The developed cloud is shown in the first thumbnail. The day was also dominated by altocumulus perlucidus (second thumbnail) related with the latter low pressure but unrelated to the cumulus clouds. However, such altocumulus clouds normally indicate that a thunderstorm might be brewing up though no thunderstorms had occured on the day. A small funnel cloud had also developed as reported by the maltaweathersite Fb page as can be seen on the third thumbnail courtesy to the same site.