Formation of large cumulonimbus incus cloud with an evenly spread anvil at all sides due to light upper-level winds. This situation and hence cloud formation is rare for the Winter season and more common in late Summer and Autumn. However, in this case the jet stream was south of the Maltese Islands rather than north as in late Summer. The first thumbnail shows another picture of cumulonimbus incus clouds forming from cumulus radiatus and the fourth thumbnail shows similar clouds wrapped around an area of low pressure over the Balkans due to cold air flowing from the Balkans towards the Ionian Sea. The second and third thumbnails show the weather sounding indicating instability (similar to late Summer but of course less unstable due to much cooler airmass and sea temperature involved) and thermal contrast fueled also by a steep lapse due to an upper-level cold pool of air just above the Ionian Sea and also involving the Maltese Islands. The fifth thumbnail shows strong echoes reading as a heavy hail shower developed over the Marsaxlokk area from such cloud.