Hole opened up

Rare weather phenomenon filmed over Indonesia

(Bild: kameraOne (Screenshot))

A fascinating and quite rare natural spectacle was presented to the inhabitants of the province of Jawa Timur in the east of the Indonesian island of Java on Tuesday. A strange hole suddenly opened up in the cloud cover with a white strip of cloud in the middle (see video above).

This relatively rare weather phenomenon, which is known as a hole-punch cloud or fallstreak hole and is still little researched, is probably caused by falling ice crystals. These originate either from a cloud at a higher altitude or from condensation trails created by water vapor emitted by aircraft engines.

Ice crystals responsible for holes in the sky
It is assumed that the falling ice crystals absorb water vapor from the clouds because the moisture in the air binds to the ice. In this way, oval or almost circular gaps often appear in the cloud layer where this phenomenon occurs - a so-called hole-punch cloud.

A strange hole with a white stripe in the middle suddenly appeared in the cloud cover.

(Bild: kameraOne (Screenshot))

Due to the additional water absorption, the ice crystals become increasingly heavier and fall faster towards the earth. If this process continues long enough, a funnel-shaped structure sometimes forms at the lower end of the hole-punch cloud. However, the snow does not reach the earth because it is heated in deeper layers of air and melts or sublimates directly back into water vapor.

Appearance disappears again quite quickly
However, if you want to photograph such cloud holes, which are now known as "cavum" in the International Cloud Atlas, you need to get your camera or cell phone out quickly. According to meteorologists, this weather phenomenon usually disappears after just a few minutes.

Due to their elliptical appearance, fallstreak holes are sometimes mistaken for UFOs.