A hole punch cloud, officially known in the World Meteorological Organization’s International Cloud Atlas as a cavum, is a rare atmospheric phenomenon characterized by a large circular or elliptical gap appearing in mid- to high- level cloud layers.

Also referred to as a fallstreak hole, skypunch, or cloud canal, these formations look as though a massive cookie cutter has stamped a clean hole out of a uniform sheet of clouds.

Hole punch clouds are a fascinating mix of physics, meteorology, and human aviation. They require a specific recipe to occur:

Supercooled Water: The phenomenon takes place in thin layers of altocumulus or cirrocumulus clouds. These clouds consist of supercooled water droplets, water that remains in a liquid state despite being far below the freezing point (0°C / 32°F).

The Disturbance: Supercooled droplets are highly unstable and will flash- freeze instantly if disrupted. While higher ice clouds can drop natural ice crystals into the layer below, the most common trigger is a passing aircraft.

The Chain Reaction: As an airplane punches through the cloud, air expanding over its wings or propellers rapidly cools. This intense temperature drop causes the water droplets to instantly freeze into heavier ice crystals

The Evaporation Process: Through a phenomenon called the Wegener-Bergeron-Findeisen process, these newly formed ice crystals aggressively absorb moisture from the surrounding air. This dries out the local atmosphere, forcing neighboring water droplets to rapidly evaporate and widening the hole.

The Fallstreak (Virga): The heavy ice crystals eventually descend from the center of the newly formed gap, creating wispy, ghost-like streaks of precipitation called virga. Because the air below is usually dry, this falling ice or snow evaporates or sublimates before ever reaching the ground.

While they look otherworldly and are often mistaken for UFOs or secret military experiments, hole punch clouds are well-documented and completely natural environmental interactions. They are most commonly spotted near major airports or underneath busy high-altitude flight corridors where planes frequently pierce through appropriate cloud layers. If an airplane flies horizontally through the cloud layer rather than climbing or descending through it, the resulting gap can stretch into a long, linear highway in the sky known as an ice canal or canal cloud.

Their striking, clean- cut symmetry and the central wispy trails make them one of the most common causes of UFO sightings and conspiracy theories worldwide.

When a perfect circle suddenly opens up in an otherwise flat, grey sky, often trailing a glowing or shimmering mist in the center, it easily mimics the popular imagination of a spacecraft breaking through the atmosphere or a weapon firing from above.

Why They Spark UFO Rumors?

Geometric Precision: Nature rarely looks like it was cut with a laser, so the sharp, circular, or elliptical edges look highly artificial.

The Central Mist: The falling ice crystals (virga) in the middle can catch the sunlight at sunset or sunrise, creating a glowing, fiery, or metallic pillar that looks like a propulsion trail or a tractor beam.

Sudden Appearance: A hole can form and expand to be several kilometers wide in less than an hour, making it seem like a sudden “event” occurred in the sky.

Fallstreak holes are not the only clouds that trigger alien rumors. Several other rare formations regularly confuse onlookers:

Lenticular Clouds (Altocumulus lenticularis): These smooth, lens-shaped clouds form over mountains and look exactly like classic flying saucers. They can even stack on top of each other like a pile of UFOs.

Scud Clouds: Low, detached, irregular cloud fragments that move rapidly below a storm path. People frequently mistake their dark, ragged shapes for low- flying craft.

Roll Clouds: Long, low, tube- shaped horizontal clouds that look like a giant, rotating alien mothership rolling across the horizon.

Lenticular Clouds (The “Flying Saucers”)

Lenticular clouds (Altocumulus lenticularis) are the undisputed champions of cloud-based UFO sightings. They form when moist air flows over a large geographic barrier, like a mountain range. The air is forced upward, cools, and condenses into a smooth, stationary lens or saucer shape that sits perfectly still above the peak while high winds blow right through it.

Fallstreak Holes (The “Atmospheric Portals”)

Fallstreak holes open up a stark, clean-cut gap in an otherwise uniform cloud layer. Because they often feature a column of wispy ice crystals falling directly down the center, people frequently mistake them for a spaceship cloaking or an energy beam punching through the sky.

The photo was taken by viewer Phil Lambert and initially went viral after being broadcast by the local news station WBTV on November 11, 2019. It caused a massive stir on social media at the time, with many residents rushing to report it as a potential UFO or a rotating tornado due to its stark, isolated oval shape hovering directly over the highway.

The Historic Sighting That Started It All

The very origin of the term “flying saucer” is directly tied to a famous sighting near a mountain known for lenticular clouds.

On June 24, 1947, a private pilot named Kenneth Arnold was flying his small plane near Mount Rainier in Washington State. He reported seeing nine brilliant, flashing objects flying in a chain at incredible speeds. When describing how they moved to journalists, he noted that they flew erratically, “like a saucer would if you skipped it across the water.”

The press ran wild with the phrase, coining “flying saucers.” While Arnold maintained he saw solid objects, Mount Rainier is one of the most famous breeding grounds in the world for massive, stacked lenticular clouds. Meteorologists and skeptics have long pointed out that a chain of catching- the- sun lenticular wave clouds along the ridge perfectly mirror what Arnold likely witnessed from his cockpit.