Fallstreak Hole – Hole Punch Cloud

Courtesy: Beth Siple

There was an awesome fallstreak hole (in the clouds) – also known as a hole punch (cloud) Friday afternoon, visible from Kent, E. Ionia and SW Montcalm Counties in West Michigan.  I got over half a dozen pics. at bill.steffen@woodtv.com and the station got a number of pics. as well.  I also got several pics. on my facebook page.   Thanks so much for sharing.  The top pic. is from Beth Sible near Greenville.  In this picture the sun’s light is being broken into component colors (a “sun dog”) – looks like a rainbow.  It will look different viewed from different angles.

  This is from Erin N. Wiseman-Parkin.  A fallstreak hole occurs when part of a cloud made up of (super-cooled) water droplets freezes into ice crystals.  The ice crystals are heavy enough to fall as a streak. The hole and streak of cirrus (ice crystal) clouds form quickly.

This pic. is from Mike Mallory near Greenville.  It’s been speculated that many of these fallstreak holes are caused by aircraft. A plane climbing or descending through the clouds causes this.   The expansion of air passing over the aircraft wings and (for certain types of plane) over the blades of its propellers, causes the cloud around it to cool – changing the super-cooled (below freezing) water droplets to quickly turn to ice crystals.  The air around the frozen fallstreak sinks and warms up, the droplets there evaporate leaving a clear circle surrounding the cirrus streak.  When a plane passes through the cloud layer at a shallow angle, it can cause a straight line to be cut from the cloud rather than a circle.  This is known as a canal cloud.

This is a Lake Michigan satellite pic. from Fri. PM – showing the high and mid-level clouds and a few jet contrails.

  This pic. is from Kevin Varner

And this one from John Bagin in Rockford.

And another from Sarah Kent near Greenville.



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