Nashua Punch Hole and Fallstreak

December 26, 2007


Provided and copyright by: David Tiller
Summary authors & editors: David Tiller, Jim Foster

The photo above shows beautiful examples of both a punch hole and a fallstreak. It was taken from Nashua, New Hampshire on August 9, 2007, at approximately 4:00 p.m. (Eastern Daylight Time). Falling ice crystals instigated this curious hole (punch hole). Such crystals could have fallen from a higher cloud level or from a passing jet aircraft. Supercooled water droplets in the shallow cloud layer freeze as the crystals pass through. This freezing releases heat (this heat is called the "latent heat of fusion") which then warms the air, thus evaporating the surrounding cloud. The darker, gauzy appearing cloud near the center of the hole is referred to as a fallstreak and was produced by the falling ice crystals sublimating in the drier air just beneath the cloud deck.