Is the truth out there? Photos have emerged of a bizarre cloud formation over Illinois on December 1, 2017… The strange snapshots have popped up across Twitter and show a bright, unusual hole in the otherwise undisturbed clouds across different parts of the US state. Now curious-minded folks are speculating about the cause of the strange hole punch cloud phenomenon.
Also known as the Fallstreak Hole, this rare amazing and rare cloud formation appears like circular, pentagram or elliptical clearings in the cloud cover, looking like UFOs, sky holes and cloud circles.
Such holes are formed when the water temperature in the clouds is below freezing but the water, in a supercooled state, has not frozen yet due to the lack of ice nucleation. When ice crystals do form, a domino effect is set off due to the Bergeron process, causing the water droplets around the crystals to evaporate: this leaves a large, often circular, hole in the cloud.
Of course, because of their rarity and unusual appearance, fallstreak holes have been mistaken for or attributed to unidentified flying objects. And in this case again! Keep your eyes to the sky to observe such amazing phenomenon.
SOURCE: http://strangesounds.org/2017/12/hole-punch-cloud-illinois-pictures.html
