https://maltaclouds.net/wp-content/uploads/2018/09/Cb-base3-1.jpg?v=156992004015362048adminhttp://maltaclouds.net/wp-content/uploads/2018/10/logo-1-300x138.pngadmin2014-04-18 17:21:202018-11-10 17:23:50Cb cloud base
Formation of a cumulonimbus capillatus incus praecipitatio cloud, the latter two being accessory feautures to describe the cloud, which looked more wide than it was high. In fact, it barely fitted even on a panoramic photo. The species Cb was confirmed as thunder was heard from it. The first thumbnail is a professional single shot photo showing the extreme left hand side of the cloud looking as if it consisted of multiple towers of rising air thermals making it a Multicellular thunderstorm with the multiple cells being in different stages of the life cycle starting from small cumulus clouds on the right and ending into fully mature storm cells towards the left. The second thumbnail is a sunset photo taken on the same day showing a completely submerged countryside due to a very wet start to Autumn. In Mosta, where the photo was taken, more than 60mm of rain were recorded at night of the previous day resulting in this photo. The third thumbnail shows altocumulus clouds that seemed to be forming out of the top of cumulus congestus clouds or shallow cumulonimbus that was still giving precipitation, such cloud would be known as altocumulus stratiformis perlucidus cumulomutatus. The fourth thumbnail shows a potentially cumulonimbus murus cloud identified as such by the abrupt lowering of the cloud edge in the background. However, one must note that the foreground cloud is cumulus congestus with widespread altostratus nebulosus being the anvil of other former Cbs.
This weather situation was caused by a cold pool of air that sat directly above the Maltese Islands as indicated by the 500mb chart of the fifth thumbnail. In turn, this cold pool made the atmosphere over the Maltese Islands unstable as indicated by the weather sounding of the sixth thumbnail showing that cumulonimbus clouds were able to form at heights between 823 metres and 8300 metres. Little wind shear was present excluding the formation of waterspouts at the time with a NE wind at all atmospheric levels ranging between Force 4 and 5 enabling isolated slow-moving heavy showers. At one point, the centre of the low pressure was over the Maltese Islands as per SLP chart of the seventh thumbnail. The eight and ninth thumbnails are the satellite image and the visible one respectively showing a swirl of clouds directly over our Islands and cumulonimbus clouds which were encircling our Islands as the centre had moved rather quickly during the day.