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Standing wave and lenticular clouds
Posted: 08 Mar 2015, 11:31
by cstorey
Yesterday we had an extraordinary display from a standing wave resulting from a SW wind over the Welsh Mountains
At first I thought that the biggest one was a mammatus, but on closer inspection it turned out to be 2 or 3 lenticulars layered one on top of the other
Re: Standing wave and lenticular clouds
Posted: 08 Mar 2015, 11:42
by Airspeed
Rather spectacular, those lenticulars!
I thought that they normally form over peaks of mountains; can't see one below those clouds. Maybe it's out of frame, or maybe I'm wrong again.
Thanks for posting, Chris.
Re: Standing wave and lenticular clouds
Posted: 08 Mar 2015, 12:16
by DaveB
Can't ever recall seeing anything so surreal Chris. Lovely phot
ATB
DaveB

Re: Standing wave and lenticular clouds
Posted: 08 Mar 2015, 14:04
by Dev One
Thats the result of a SW'ly over Snowdon & its compatriots I should think.
If it comes from the NE it gives Rotor turbulence at Llanbedr....possibly not good for the proposed Space Port?
Not that it happens that often though, probably about as often as Lenticulars over the Wirral!
Keith
Re: Standing wave and lenticular clouds
Posted: 08 Mar 2015, 14:05
by cstorey
Mike : the pic was taken facing slightly S of W, and the mountains are about 20NM southwest of us, so that these clouds were perhaps 5 to 10 NM downwind of of the northern face of the Snowdonia mountains . That they were the result of the wave was shown by the fact that they lasted the whole afternoon without moving . The whole of the border country between England and Wales can be subject to quite spectacular wave now and then . In the 1970s I can well remember travelling South along the border on what was then called airway Amber 25 and having the slightly unnerving experience of passing gliders from a site called Long Mynd at well in excess of 18000 feet ! I also on another occasion had an Eagle go over the wing in the same area at about the same altitude
Dev : I have on much rarer occasions seen rotor in this area : not something that I ever intended to ( or did ) tangle with
Re: Standing wave and lenticular clouds
Posted: 08 Mar 2015, 19:44
by Dev One
cstorey wrote:
Dev : I have on much rarer occasions seen rotor in this area : not something that I ever intended to ( or did ) tangle with
Having worked at Llanbedr for nearly 20 years, rotor was certainly uppermost in our minds with a North easterly before launching a Jindivik.
On one occasion a 1-11 from Farnborough was told to watch out for a rotor & very nearly pranged it when he poo pooed it!
Keith
Re: Standing wave and lenticular clouds
Posted: 08 Mar 2015, 21:09
by nigelb
Fantastic picture, Chris. For a moment, before I cleaned my glasses, I thought it was a diaphanous UFO!
Nigel²
Re: Standing wave and lenticular clouds
Posted: 09 Mar 2015, 10:59
by Airspeed
Further reading has introduced me to coffin corner and other terms previously beyond my ken.
Another educational foray, thanks to this forum.
Also, apologies Chris, your initial caption mentioned the wind and nearby
mountains.
My comment was due to puzzlement, and I thank you for your restraint and patience in explaining further.
This oversight was made by a casual observer, (not employed by the Daily Mail, BTW).

Re: Standing wave and lenticular clouds
Posted: 10 Mar 2015, 20:45
by simondix
If you like clouds you should like this. Somebody obviously saw the same cloud.
http://cloudappreciationsociety.org/
Re: Standing wave and lenticular clouds
Posted: 11 Mar 2015, 11:35
by cstorey
Yes, very interesting ; the photo by Joe Sillitoe was obviously taken at about the same time, and from a position about 1 mile W of mine. I had a fascinating evening about 2 years ago when at a dinner we found ourselves sitting next to Gavin Pretor Pinney and his wife. I never realised that you could make a living from books on clouds !