I too have always regarded CAVOK as a pretty useless abbreviation, taking no
account of a lot of aviators, especially trainees, whose flight may be
compromised by hazy conditions, vis below 20km say, and meteorologists
whose knowledge of the conditions may be severely curtailed by not knowing
that there was OVCAc070, for instance. Most pilots I have spoken to on this
topic would like the real visibility to be included in all METARS.

--
Bernard Burton
Wokingham, Berkshire, UK.

Satellite images at:
www.btinternet.com/~wokingham.weather/wwp.html
"Martin Rowley" wrote in message
...

"Norman Lynagh" wrote in
message
0530z CALM 4000 HZ 4Ci300 14.9/14.2 1021
RMK: Difficult to decide on how much Ci there is because
the haze makes the sky very milky. It feels as though
it'll be a real stinker today. Not my sort of weather!

0900z SW F2 15km -HZ SKC 26.3/16.6 1020

... we used to hate mornings/days like this when briefing for RAF
low-level training sorties over northern & Midland England. Although the
'Met Vis' was usually "reasonable", the dense haze extending to some
considerable height used to mean that aircrew found conditions virtually
useless for extended LL flight, particularly when flying towards the sun
(as the earlier sorties would have been). Until the temperatures rose
sufficiently to mix the lower air, an entire morning's training could be
lost, and on some days (and today is a good example), an entire training
package could be aborted. And yet, civil airfields all around us (in
Yorkshire) were reporting ... CAVOK!!

Martin.


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