The awesome fall streaks look like angels looking over us.
Also called Virga, these fantastic clouds were photographed over New Hampton, Iowa on September 14, 2014.
Did you also see these strange looking clouds? These are fall streaks or virga…
This weird sky formation are cloud precipitation that does not reach the ground. The streaks can be raindrops, snowflakes or even halo forming ice crystals.
When the air beneath the cloud is warmer or otherwise less humid the falling drops evaporate. This was exactly the case over New Hampton, Iowa tonight:
The fall streak’s characteristic hooked shape arises because drops fall progressively slower as they shrink. For small drops in laminar flow the downward velocity varies as the square of their diameter – Thus the downward velocity reduces rapidly as the drops get smaller.
While this is happening the wind carries the fall streaks sideways. After almost complete evaporation, the streak’s tail is almost horizontal. Did you also see these weird clouds in the sky?