Formation of a cumulus congestus cloud at sunset as Malta was situated inside the cold-sector of a low pressure system as clearly evidenced on the visible satellite image of the fourth thumbnail. The weather sounding on the third thumbnail reflected this indicating low-level instability with the cloud level estimated at between 0.9km and 1.5km but the cloud top could have been higher up to 2.8km. Notice that the cloud was spread from one horizon to the other hence becoming cumulus congestus radiatus, indicating a common lifting mechanism or alignment with the prevailing cold WNW wind. The first thumbnail is the same line of cumulus congestus taken minutes later showing the cloud tower forming a hood probably meaning that it reached stability hence unable to grow further into a thunderstorm cloud. The second thumbnail look like low-level altocumulus floccus clouds formed by heat thermals rising from the surface. There was an overhead jet stream keeping the low pressure system alive.