Mystery and rare Fallstreak hole cloud phenomenon over Stockton – May 9 2014
A fallstreak hole, also known as a hole punch cloud, punch hole cloud, skypunch, canal cloud or cloud hole, is a large circular or elliptical gap that can appear in cirrocumulus or altocumulus clouds. One was just spot in the sky over Stockton, California on May 9, 2014.
A weird weather phenomenon was observed by many in the sky over Stockton, California on May 9, 2014.
After receiving bunch of pictures News10 ABC asked around to decrease the fear of Stockton residents.
Now, NOAA has an idea of what it could have been. This weird cloud phenomenon was most probably created by ice crystals falling through a hole punch cloud, refracting light.
How punch hole cloud form?
According to Wikipedia, a fallstreak hole is a rare, large circular or elliptical gap that can appear in cirrocumulus or altocumulus clouds. Such holes are formed when the water temperature in the clouds is below freezing but the water has not frozen yet due to the lack of ice nucleation particles. When ice crystals do form it will set off a domino effect causing the water droplets around the crystals to evaporate: this leaves a large, often circular, hole in the cloud.