In the past month, there have been over 50 reported UFO sightings in Texas - and meteorologists think they know the reason.And it's not very exciting. They were clouds. Weird clouds, yes. But just clouds.The bizarre formations in the sky over America's Lone Star State sparked reports of alien spaceships hovering ominously - and the strange shapes, to be fair, do look like flying saucers.One Texan on Twitter wrote: "Woah! The sky over Texas appears to be FILLED with UFOs!"But weather experts claim unusual pressure systems have caused lots of lenticular clouds, which are rare, circular clouds that appear and dissipate in the blink of an eye.Lenticular clouds are caused when warm moist air encounters a barrier such as a mountain or even cooler air.However, this has not stopped some conspiracy theorists from claiming that the clouds are still UFOs, reports the Daily Mirror One even said that the clouds are formed by aliens 'cloaking' their spaceships. Some still persist with such outlandish claims on websites like inquisitr.com, and the Mutual UFO Network (MUFON).Fletcher Gray, MUFON's volunteer chief investigator for Texas, said: "When we have a low (pressure system) like that, with the upper atmosphere as cold as it was, and with all that hail and rain in the last four to five weeks, you get those strange cloud formations. Those are common."Some of the reports are obvious fakes, he said, such as the man who sent a photo of a dustbin lid with green paint on it, trying to pass it off as a UFO."You could see the handles on the lid," Gray said.