Formation of spectacular lee waves clouds, probably stratocumulus undulatus clouds, as seen over Sicily and to a lesser extent also over the Maltese Islands. As per first thumbnail, only normal cumulus clouds were observed from the ground in the Maltese Islands and there were no reports of spectecular or strange clouds in Sicily, perhaps the undulations were too much seperate from each other for a spectecular cloud photo from the ground. In any case, these clouds were formed because of an unusually persistent Mistal gale over the area in its fourth consecutive day as it blew from mountainous areas under high relative humidity. This resulted in water vapor to rise rapidly from the lower layers of the atmosphere, aided by convection heating from below towards the high altitudes, and then continuously oscillating for hundreds of kilometers to reach Sicily. No unusual features were indicated in the weather sounding which is shown in the last thumbnail.