Gary Edstrom wrote:
On 30 Sep 2006 15:35:11 -0700, "Weatherlawyer"
wrote:


Gary Edstrom wrote:
What kind of cloud formation is this?

http://gbe.dynip.com/weather/R3442A.JPG

I have been scanning some of my old 35mm slides and came across this one
I took out in Westlake Village, California back in November 1983. The
feathery appearance really made it look different. I know little about
weather and wanted to ask someone what it was. But, it was forgotten
about until this morning when I happened to scan it. So, can someone
tell me 23 years after the fact what it was?

A contrail. Plenty of discussion about them on usenet.

I had considered the possiblity of a contrail, but I had never seen one
like this, so I dismissed the idea.

They are very common in my neck of the woods on a flightpath from
Liverpool and Manchester Airports.

No matter how many engines, there is always two parts to a contrail as
the pressure is two circles under the wings. They equate to the weight
of the aircraft -these days that is hundreds of tons of air pressure.

However it has to occur in conditions condusive to stratus to be long
lasting.