Cloud mosaic (wave-like features) at a height of around 2.5km due to wind shear as wind was changing direction with height from NW to WNW and increasing slightly in speed. Althaugh the air at that level was not that moist, the clouds still have formed due to lots of desert dust as seen in the visible satellite image combined with rising air motion as a modest upper level trough was passing over the Maltese Islands. The weather quickly cleared later on.