Fall Streak Hole

Dollsworth - Public Domain

Dollsworth – Public Domain

Cloud of the Day – Fall Streak Hole

Pfranson - CC-BY-SA

Pfranson – CC-BY-SA

A fall streak hole can appear in altocumulus or cirrocumulus cloud. It looks as if part of the cloud just fell out, leaving a hole. Often you can see streaks of ice crystals extending down below it. A fall streak hole is also known as a hole punch cloud, a skypunch or a cloud hole, among other names.

Beckachester - CC-BY-SA

Beckachester – CC-BY-SA

The hole is caused by the sudden freezing of super-cooled water in the cloud. Water can cool to well below freezing without forming droplets or crystals if there is no source of nucleation to allow it. The sudden introduction of a nucleation process sets off a domino effect, and the hole and fall streaks can form very rapidly. One source of nucleation is the disturbance caused by a passing aircraft.

H. Raab - CC-BY-SA

H. Raab – CC-BY-SA

Other than its association with the mentioned cloud types, a fall streak hole does not signify any particular kind of weather. Neither does it indicate that a UFO just punched through the cloud.

Kittelschürze - CC-0

Kittelschürze – CC-0

Tap pictures for large originals.

rjb

7 comments for “Fall Streak Hole

  1. Anonymous
    July 27, 2015 at 21:53

    WOW! These are so cool! I have never seen anything like them. Guess I don’t look up enough 😉

    • July 27, 2015 at 22:22

      Thank you, Someone. I knew someone would like it.-)

      rjb

  2. July 28, 2015 at 00:07

    WOW is right! Super awesome.
    I hope I get to see one of those…
    I think it’s a daydream portal.
    In fact, I’m sure of it.,)

    • July 28, 2015 at 11:18

      So, whenever you catch yourself daydreaming, run outside and look up.

      • July 29, 2015 at 11:28

        I’m always looking up to lalaland, you know that.

        • July 29, 2015 at 12:02

          Yeah. There could be sprites. Something like that, how could they resist?

          • July 30, 2015 at 04:21

            Precisely!

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