Do You Know your Clouds

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John Wallis
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Do You Know your Clouds

Post by John Wallis »

Do you know your clouds or are they just white fluffy things that float around the sky and mean nothing to you?

With all this unstable weather about and endless days of massive CB build up, flash floods, thunder, lightning and the odd locust I thought it might be worth reflecting on the danger of certain cloud types.

Without doubt the main danger for our type of flying comes mainly from CBs and large cumulus. With there being so much low pressure around and a strong sun the clouds are free to go ballistic and build to great heights. For those that don't know, the danger of being pulled into a large cumulus is bad enough as they are full of moisture/ice and turbulence. There is no visibility and you could be pulled up to a great height and even die from hypothermia.

If you get pulled into a CB there is a very real chance of death from not only the cold and turbulence but more dangerously the shear layers in these clouds. Imagine an updraft rising at speeds of 50 knots and within a very small distance a downdraft descending at the same speed? These are the forces that would rip an aircraft wing in half. You've got to ask yourself what would it do to a paraglider and it doesn't bare thinking about.

In weather like we've got at the moment and you are in a thermal screaming up to cloud base be careful. If the vario reads stronger and stronger lift the closer you get to base you will have to take drastic action or face being pulled into cloud and a horrible experience. In the ideal world when we have high pressure and and sensibly sized cumulus the closer you get to cloud base the lift should weaken which allows you to play about on the edge of the cloud having a pleasant and uplifting experience.

There's danger with other types of cloud too such as wave rotor. Have a look at the link below as it contains some excellent info on cloud types and there meaning.

One of my favorites is Pileus clouds. It's just one of those things that stuck in my head from years ago. Can anyone describe it without doing a search?

http://ww2010.atmos.uiuc.edu/(Gh)/guide ... /home.rxml
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“If you always do what you’ve always done, you’ll always get what you’ve always got.”
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AlastairW
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Post by AlastairW »

There have been some bloody scary clouds around recently..... The Marge Simpsons as Brian Day calls them.....

If a cloud is taller than it is wide.... AVOID it.....

And if all of a sudden it starts getting really easy to stay up, you have not suddenly become a sky god..... you really need to worry about getting down!

When is the weather going to change?????
It is sad to measure your life in terms of hours flown...... but even sadder not to.........
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John Watson
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Post by John Watson »

Well said John, the dangers are enormous and frightening, I remember Joe Cunningham’s story about his unintended flight in cloud on his hang glider. He described how he had hoar frost all over his wires and instruments at 12,000ft and was totally disorientated and frightened, --- Joe wasn’t the kind of bloke to get frightened too easy either.
I remember Lachens about 1995, I was winding up some lift on the side of a Cumulus - in – out - in – out – in – in – in, --- I didn’t come out for about ten very long minutes, thinking I was going in a straight line I pulled on a lot of speed to get out, I had strange pressures on my body as my harness was going positive then negative G, I looked under my chest to my compass and it was spinning fast! (o) (puke)
I have tried flying through lightish wisps of orographic where you lose site of the ground for short periods well out from the ridge on a compass bearing. Even this is difficult, and you can forget speeding up.
I have not been in cloud in my paraglider yet, and don’t particularly want too, however I do think that it may be less disorienting than a hangie as you always have it above your baldy heed.
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tony anderson
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Post by tony anderson »

Good thread John Xfell was a classic example on tues evening,very large CB build ups along the Pennines but the spreadout from the base made it look as if the launch area was only being affected by benign looking stratus.However once in the air the size and extent of the clouds was revealed .A little story about the respect we should give CBs last year in my day job ,I was landing at night into Bodrum in Turkey and had to make an approach under an active CB, the aircraft at a landing WT of 63 tons started climbing at idle power, with the nose down it should have been descending at 3000 feet per min but was climbing at 1500 feet per min only putting the landing gear out and increasing drag got me out of it.That was in an aircraft that can achieve a descent rate of 6000 feet per min,as Mr wolf said if a cloud is taller then it is wide beware .
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AlastairW
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Post by AlastairW »

You mean you can thermal in a 757 Tony????

Look forward to seeing you at X fell with one ......... :D :D
It is sad to measure your life in terms of hours flown...... but even sadder not to.........
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