On January 19, the heavens above Turkey's western Bursa province had residents pointing their phones and cameras skyward. They were looking at a rare lenticular cloud. The National Weather Service says lenticular clouds “develop within the crest of mountain waves where the air is rising.” ...

Un extraño fenómeno asombró a los residentes de la ciudad turca de Bursa cuando una nube circular, similar a un ovni, cubrió el cielo. Source

A massive lenticular cloud resembling a UFO was spotted over the city of Bursa in Turkey on Thursday, surprising citizens who captured the rare phenomenon on their phones. The circular cloud, which appeared at sunrise and featured a large hole in the middle, remained intact for about an hour. ...