An overshooting cumulonimbus cloud with a fairly rounded-shaped top. This cloud was part of unseasonable heavy thunderstorms that effected mainland Malta. The cause of this thunderstorm and hence cloud formation was a cut-off cold pool of air in the upper atmosphere that was moving very slowly across Malta. Wind at upper-levels were from the NNE hence mundane clouds falling onshore quickly became cumulonimbus clouds as they encountered the very hot surface air over Malta (Temp before the storm was 29C) and the gently rising land. Such storms are rare in Malta although in recent years, these have been less of a rarity. The cold pool combined with instability as per weather sounding helped to trigger the formation of these clouds and the thunderstorm which video could be found in the thumbnail. When the surface air profile was modified to 29C with 50% humidity, convective inhibition was completely eliminated on mainland Malta allowing the air parcel to reach the level of free convection.