The weather sounding alone in the first thumbnail shows a very typical profile for the formation of these specific mid-level clouds which are actually precipitating but whose rain or snow never reaches the ground. The air above 6.5km altitude is very moist whilst below it was very dry and it was dry for enough altitude for all its precipitation to evaporate. The fact that there was upper-level instability and low pressure approaching the Maltese Islands due to the descent of a cold airmass towards the Western Mediterranean, have created a massive altocumulus virga cloud even converging to a high altitude cumulonimbus cloud. The second thumbnail show the same cloud photo some 15 minutes later when it almost sublimed and the third thumbnail shows the more typical formation of altocumulus virga which was photographed some 25 minutes earlier before the appearance of this unusually big altocumulus virga.