Odd clouds this eve above the A14 (Northants/Cambs)?
Discussion
No, not mushroom clouds over Molesworth courtesy of NK but something else I've never seen before...
Heading west past Huntingdon, a number of what looked like very short and abrupt aircraft contrails ahead in an otherwise cloudless sky as the sun was setting. No planes to be seen and most of the 'clouds' broadly aligned in a group but a few others singly at random angles. Really odd thing was all looked to be pretty equally sized and as far as I could tell at a common height. Saw them for maybe 15 mins or so with no decay or dispersal (like a contrail does), but they did seem to drift away. Mystified me; any ideas (or anyone else see them)?
Heading west past Huntingdon, a number of what looked like very short and abrupt aircraft contrails ahead in an otherwise cloudless sky as the sun was setting. No planes to be seen and most of the 'clouds' broadly aligned in a group but a few others singly at random angles. Really odd thing was all looked to be pretty equally sized and as far as I could tell at a common height. Saw them for maybe 15 mins or so with no decay or dispersal (like a contrail does), but they did seem to drift away. Mystified me; any ideas (or anyone else see them)?
"Mountain wave" clouds?
(Aka "Lee clouds")
When air travels over an elevation, downwind the flow will undulate.
As the air rises and then falls, pressure and temeperature changes will cause condensation of water vapour - a cloud - at the top that disappears as the air falls again. This can lead to a series of similar, stationary clouds at regular intervals across the sky.
Most obvious with mountains, not the case around Huntingdon, but hills will do - you don't need a Matterhorn! -and the wave effect can travel a long way in stable wind conditions.
See "mountain waves" Google Image or YouTube.
John
(Aka "Lee clouds")
When air travels over an elevation, downwind the flow will undulate.
As the air rises and then falls, pressure and temeperature changes will cause condensation of water vapour - a cloud - at the top that disappears as the air falls again. This can lead to a series of similar, stationary clouds at regular intervals across the sky.
Most obvious with mountains, not the case around Huntingdon, but hills will do - you don't need a Matterhorn! -and the wave effect can travel a long way in stable wind conditions.
See "mountain waves" Google Image or YouTube.
John
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