This cloud formation is very typical after a cold spell in the Maltese Islands (as happened in this case) or the sudden arrival of a warm airmass. This have caused the lingering cold and moist air (from previous cold spells) to get trapped close to the ground as surface pressure rose. This weather situation led to widespread formation of stratocumulus clouds. The first thumbnail shows a cumulus cloud that stops rising once it reached the 2.2km altitude and spread out. In fact, the weather sounding depicts the perfect scenario for such clouds formation. If wind shear was also present, the clouds would have formed wave-like feautures possibly making for some dramatic scenery in the area.