"Alan White" wrote in message...
The term 'white out' is one that is becoming greatly misused and seems
to imply, in simple terms, snowing very heavily. Provided that snow is
lying, it's possible to experience a white out without any snow
falling at all. All it needs is lying snow and mist sufficiently dense
to provide omni directional lighting conditions such that no shadows
are visible and the shape and form of the ground underfoot cannot be
determined.

Alan

I once heard a pilot with the British Antarctic Survey describe their
technique for landing on the ice surface in white out conditions - basically
fly straight and at a very slow descent rate until contact is made with the
surface, no point looking out the window. Of course the 'landing strip' is
enormous and completely flat.

Karl, Orkney

On Sun, 6 Feb 2005 14:20:11 -0000, "John DH"
wrote:

What we have both encountered was 'White-Out' conditions.

That's reassuring because that's what I was describing :-)

--
Alan White
Twenty-eight miles NW of Glasgow, overlooking Loch Goil and Loch Long in Argyll, Scotland.
Web cam, http://www.ufcnet.net/~alanlesley1/kabcam.htm
Web site, http://www.alan.lesley.ukgateway.net

My wife went for a short trip in a sea plane last summer, calm day with
glassy water. The pilot used a very similar technique for landing.

John D

I once heard a pilot with the British Antarctic Survey describe their
technique for landing on the ice surface in white out conditions -
basically
fly straight and at a very slow descent rate until contact is made with
the
surface, no point looking out the window. Of course the 'landing strip' is
enormous and completely flat.

Karl, Orkney

The message
from "Karl Cooper" contains these words:

"Alan White" wrote in message...
The term 'white out' is one that is becoming greatly misused and seems
to imply, in simple terms, snowing very heavily. Provided that snow is
lying, it's possible to experience a white out without any snow
falling at all. All it needs is lying snow and mist sufficiently dense
to provide omni directional lighting conditions such that no shadows
are visible and the shape and form of the ground underfoot cannot be
determined.

Alan

I once heard a pilot with the British Antarctic Survey describe their
technique for landing on the ice surface in white out conditions -
basically
fly straight and at a very slow descent rate until contact is made with the
surface, no point looking out the window. Of course the 'landing strip' is
enormous and completely flat.

Karl, Orkney

Yes, indeed, you don't need misty/foggy conditions for 'white out'.
After all you wouldn't be flying in such a place in foggy conditions!

Reminds me of what was not an uncommon experience when glacier skiing in
South Georgia. Visibility in excess of 100 km, but the only way that we
could progress was by throwing a glove 20-30 feet ahead of us and, if it
was still visible, ski up to it, pick it up and repeat the process
(assuming the intervening 20-30 feet held no dipsetc!). If it
disapperared take care - ahead could be an unseen icefall or crevasse!

On such occasions, despite the exceptional vis, the light bouncing
between extensive snow cover and 8/8 of low AS cloud, resulted in no
variation of light from any direction, no shadows and absolutely no
definition in the snow surface. In fact we would sometimes have amusing
episodes when, thinking we were on level snow, we stopped for a break -
only to find that as we bent to lift up a rucksack it was to find them
no longer there but instead 20-30 yards behind us! While standing
talking, still on our ski, the had been slowly and imperceptably
sliding down a gentle snow slope!

Dave
Fair Isle

"Dave Wheeler" wrote in message...

Yes, indeed, you don't need misty/foggy conditions for 'white out'.
After all you wouldn't be flying in such a place in foggy conditions!

Dave

See what one of your former Loganair pilots does to get away from our
northern winter!

http://www.mpaviation.com/aarctic.htm

(Still 'on topic' as these are weather photos!)

Karl

Want to swop jobs!

John D

See what one of your former Loganair pilots does to get away from our
northern winter!

http://www.mpaviation.com/aarctic.htm

(Still 'on topic' as these are weather photos!)

Karl

Alan White wrote:

On Sun, 6 Feb 2005 10:35:40 -0000, "John DH"
wrote:

...even white-out in the west at times,...

The term 'white out' is one that is becoming greatly misused and seems
to imply, in simple terms, snowing very heavily. Provided that snow is
lying, it's possible to experience a white out without any snow
falling at all. All it needs is lying snow and mist sufficiently dense
to provide omni directional lighting conditions such that no shadows
are visible and the shape and form of the ground underfoot cannot be
determined.

I've only experienced a true white out once, on the summit of Beinn
Narnain (848m), and it was quite interestingly scary. My partner
appeared to be suspended in space, because ground and mist merged
seamlessly, and even foot prints in 10cms of snow were invisible.
Navigation, with a complete absence of any sort of landmark, was
interesting to say the least.

I would hate to think that a phenomenon that is quite rare was being
dumbed down to something that occurs relatively frequently.


Agreed. I first came across the term about 50 years ago in my /Observer's
Book of Weather/ but have never seen the phenomena. Since I can't find the
reference in that book I'll have to make do with the following from the Met
Glossary, 1972.

White-out: A term applied to that condition in which the contours and
natural landmarks in a snow-covered region become indistinguishable. The
associated meteorological conditions appear to be a uniform layer of
relatively low cloud; under such conditions the light which reaches the
surface arrives in nearly equal measure from all directions, with a
resulting absence of shadows,

Graham