An unbelievable phenomenon in the sky over the city of Rethymnon on the island of Crete. A covered UFO? A saucer made of cloud particles or a UFO cloud?
The very rare phenomenon, a cloud in the shape of a UFO, occurred the other day and the amazing pictures were shot by Giannis Gkikas.
This rare saucer-shaped, lenticular cloud is sometimes called UFO cloud. It typically forms where stable moist air flows over a mountain or a range of mountains.
A UFO cloud forms in the troposphere, typically in perpendicular alignment to the wind direction.
Pictures uploaded on meteorkrites.gr, a group of hobby weather watchers.
Citing members from Meteorrites, Cretapost notes that such UFO clouds have been formed also in the past in the area due to the winds blowing from the South.
The scientific explanation for the UFO clouds formation is that where stable moist air flows over a mountain or a range of mountains, a series of large-scale standing waves may form on the downwind side. If the temperature at the crest of the wave drops to the dew point, moisture in the air may condense to form lenticular clouds. As the moist air moves back down into the trough of the wave, the cloud may evaporate back into vapour. Under certain conditions, long strings of lenticular clouds can form near the crest of each successive wave, creating a formation known as a “wave cloud.” The wave systems cause large vertical air movement, enough that water vapour may condense to produce precipitation.
The clouds have been mistaken for UFOs (or “visual cover” for UFOs), particularly the round “flying saucer”-type, because these clouds have a characteristic lens appearance and smooth saucer-like shape; also, because lenticular clouds generally do not form over low-lying or flat terrain, many people have never seen one and are not aware clouds with that shape can exist.
PS I can assure you: I was never aware that such clouds exist and have never seen one!