Cwmbran sky 'smoke-like' trail explained by aviation expert

Nicky Deacon, one of the members, shared a photograph of the sky across Cwmbran on Monday morning. 

"How strange is this in the sky across Cwmbran this morning? Totally weird," he said. 

The sky over Cwmbran with the trail (Image: Nicky Deacon)

Julian Yalland commented: "I seen that this morning going across the river Severn.

"It was coming from a plane, it was white to start with then went black/grey."

In the comments, others speculated about what the 'smoke-like' trail was, with some calling it chemtrails. 

Owen Edmonds said: "It's chemtrails. However, it hasn't changed colour, it's just the sunlight hitting it at different angles. Nothing to worry about."

Following the discussion in our camera club, Neil Hooper shared a spectacular photograph in Blackrock. 

The incredible photograph of the sky at Blackrock (Image: Neil Hooper)

A spokesperson for the UK Civil Aviation Authority explained the phenomenon: 

"When people see trails caused by aircraft in the sky it is the formation of condensation trails, known as contrails.

“Contrails occur in specific atmospheric conditions when the air is ice-supersaturated.  

"The ice crystals coalesce around small soot particles which are emitted from aircraft engines as part of the combustion process.  

"The shape of a contrail can be affected by several different factors, including the temperature, the humidity and the wind.”

If the air is dry (low level of humidity) the trail will only appear, if at all, as a short plume behind the aircraft. 

However, if the surrounding air is at, or close to saturation (high level of humidity) the contrail will evaporate slowly, or not at all, and will be long and persistent, occasionally spreading into a cirrus like cloud.