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Posts tagged ‘Evaporation’

Reverse contrails – a new cloud type?


I’m not sure whether I have classified a new cloud type, or I’m just naming it incorrectly but this shot was sent in from Halling, in north Kent on 25th July 2011.  It is certainly a sight that it not often seen in the sky.

What we’re looking at is a layer or alto cumulus but that’s not what caught my eye.  The 2 darker streaks across the sky are the opposite of contrails – or as I now like to call them ‘Reverse contrails’.   We’re all familiar  with aeroplanes creating condensation trails (contrails) across the sky, but here is the opposite.  In this situation the upper atmosphere has a high moisture content and therefore when the aeroplane flew through the cloud the heat from the engines caused the water droplets within the cloud to evaporate.  Therefore instead of creating a condensation trail, the plane destroyed the cloud that was already there, leaving a ‘clear trail’ not a ‘contrail’.

If anyone knows what this is technically called I’d love to know –  Thank you.  That’s the fantastic thing about weather…there’s still so much to learn!

A suggestion has been ‘distrails’ – but also that it could even be the shadow of a contrail at a higher level above the cloud layer.   So potentially we can’t see the contrail, just the shadow it is creating on the cloud below…interesting…

Please continue to join in the discussion!

Don’t you think this could’ve looked like the Union flag? (Do The Red Arrows do that in their displays?)  Spot the England flag too – very patriotic!


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