Rare “Fallstreak Hole Outbreak” Spotted Over Southern Manitoba

Southern Manitoba sky-watchers were treated to a rare atmospheric spectacle the morning of Dec. 1 as several “fallstreak holes”, also known as punch-hole clouds, appeared across the region. After receiving multiple public reports, the Weather Centre of Manitoba Facebook group reviewed satellite imagery and confirmed a small outbreak of the unusual formations between sunrise and noon.

Most of the activity occurred north of Winnipeg, where the distinct circular gaps briefly punctured mid-level cloud layers, drawing attention from photographers and weather enthusiasts.

Fallstreak holes form under specific atmospheric conditions and, despite their dramatic appearance, are completely natural. They occur when a layer of supercooled water droplets, liquid water suspended below the freezing point, suddenly freezes into ice. This rapid change is often triggered by an aircraft passing through the cloud layer: the temperature drop and pressure disturbance around the wings causes the droplets to crystallize.

Once the droplets freeze, the ice crystals grow heavier and begin to fall, leaving behind a striking circular or elliptical gap. Streaks of falling ice crystals can sometimes be seen descending through the centre, giving the phenomenon its name.

While fallstreak holes can appear anywhere in the world, several forming at once, an “outbreak” is far less common.

The Weather Centre says Dec. 1 satellite data clearly showed multiple punch-hole clouds developing over a short period of time, making the event an unusual and eye-catching moment for some lucky Manitobans.

This story was originally published in The Winnipeg Sun. It is republished under a Creative Commons license as part of the Local Journalism Initiative.