Global InformationFallstreak hole information
| Fallstreak hole (Cavum) | |
|---|---|
 Fallstreak hole over Austria | |
| Abbreviation | cav |
| Genus | Cirrocumulus , Altocumulus , Stratocumulus |
| Variety | Supplementary feature |
| Altitude | 500-15,000 m (2,000-49,000 ft) |
| Appearance | Hole in the clouds |
| Precipitation | Virga |
A fallstreak hole (also known as a cavum,[1] hole punch cloud, punch hole cloud, skypunch, cloud canal or cloud hole) is a large gap, usually circular or elliptical, that can appear in cirrocumulus or altocumulus clouds. The holes are caused by supercooled water in the clouds suddenly evaporating or freezing, and may be triggered by passing aircraft.
Because of their rarity and unusual appearance, fallstreak holes have been mistaken for or attributed to unidentified flying objects.[2]
- ^ Sutherland, Scott (March 23, 2017). "Cloud Atlas leaps into 21st century with 12 new cloud types". The Weather Network. Pelmorex Media. Retrieved 24 March 2017.
- ^ "'UFO cloud formation' filmed in Romania (subscription required)". www.telegraph.co.uk. 26 October 2009. Retrieved 13 October 2021.