Formation of dark cumulus clouds with very localized heavy rain showers (covering areas even smaller than a football ground) that developed over mainland Malta. These clouds were observed to form in late Summer and Autumn under a broad level high pressure system with very light winds. Althaugh these clouds had a very dark grey base with the threat of bringing heavy storms, no lightning strike occured on the day as the air was only marginally unstable. Through the weather sounding, these clouds were no thicker than 2000 metres with their base at 600 metres and topping at 2600 metres and their dark base might have been due to the low sun angle of November giving the thick cloud illusion. The wind was blowing from a SW direction and developed further on land due to surface heating aided by a warm sea on top of a cooler airmass generating slight instability.