'Hole in sky' amazes scientists

[Ivan Seeking]

A giant hole that appeared in a uniform layer of cloud over Mobile, Alabama, in the US, has left scientists puzzled.
Local resident Joel Knain said as he took pictures: "I immediately realised that I was seeing something unique."

Meteorological experts believe the hole formed when ice-crystals from a passing plane fell through the cloud, causing the water droplets in it to evaporate. [Continued with picture]

http://news.bbc.co.uk/1/hi/sci/tech/3394461.stm

[LURCH]

Pretty freaky-lookin'. I think an air current is a more likely explanation than aircraft exhaust. Some downdraft resembling a larger, slower-moving version of a microburst.