Amazing 'fallstreak' cloud formation over Australian state baffles local residents

Unusual phenomenon is called a fallstreak hole, or the more literal 'hole punch cloud' and had some locals fearing the rapture

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The Independent Online

Amazing photographs have emerged capturing one of the sky’s rarer sights – a cloud formation known as a fallstreak hole.

Also known as a ‘hole punch cloud’ the unusual occurrence, which appears in the sky as an ethereal groove gently capturing a mini-rainbow, is formed when tiny water droplets freeze suddenly into ice crystals and drop rapidly through the air, leaving behind the appearance of a hole.

Residents of seaside town Wonthaggi, in Victoria, Australia, were quick to take to social media to capture the unusual event at around lunchtime yesterday.

As well as admiring the beautiful shape, some citizens were concerned this could herald the end of the world with one tweeting: "Rapture's here, folks."

The unusual cloud formation

Fortunately, it was nothing so exciting.

Fallstreak holes happen usually in high or mid-level clouds, which are composed of water droplets that are already at a temperature colder than freezing.

These ‘supercool’ droplets are frozen  when – for example – a plane passes through the cloud and brings with it ice crystals which causes the water droplets to freeze. This process is known as seeding according to Science Magazine.

Bureau of Meteorology’s Neil Bennett said to Perth Now: “It doesn’t occur often so it’s no wonder that it’s causing quite a stir.”

Is it the end of the world? No, its a fallstreak


Michael Efron, also from the bureau, said to Australian newspaper The Age: “The rainbow inside the cloud is called ‘iridescence’”. He explained the effect most often occurs in soap bubbles, butterfly wings and sea shells.

"This type of [cloud] iridescence occurs with high level cloud and with diffraction, [meaning] that water droplets are gathering light," Mr Efron said.