On Monday, 10 July 2017 17:14:46 UTC+1, wrote:
On Mon, 10 Jul 2017 08:35:41 -0700 (PDT)
Freddie wrote:

On Monday, 10 July 2017 15:34:24 UTC+1, Graham P Davis wrote:
On 09/07/17 19:44, Norman Lynagh wrote:
Graham P Davis wrote:

On 09/07/17 13:18, Ron Button wrote:
The old scientific law of "what
goes up must come down" was used to explain how at least half the sky
would be be cloud-free due to the descending air
The descending air doesn't necessarily occur in the vicinity of the cloud
formed by the ascent of the air, though. I used this argument when I was
being trained, but was told to carry on using the rule of thumb (I didn't!).
I can see the logic behind what you are saying, but I would argue that it
only applies to cumulus of limited vertical and horizontal extent - which is
probably more often than not. I can't see any problem with reporting 8/8 Cu,
but I would expect to only do it when the air was unstable to some depth, and
I would expect to be reporting precipitation at the same time.


As a fully trained observer
I'm one of those too :-)

8/8 Cu and raining would normally be reported as 8/8 St or 8/8
Ns. Actually 8/8 Cu would be a sockiing big Cu
If you saw it coming and your celestial dome was limited I would say report it.