Trevor Harley wrote:
On a more general note, I am glad I am not the only one having problems with
recording cloud cover, even after 30 years experience. The skies are always
more complicated than the examples you find in books and on the web. Here at
least (and I assume there is little special about Dundee) most mornings
there's a mixture of types of cloud at different levels. There are gaps of
different sizes all over the place, and I find estimating the cover on that
basis very difficult. I might decide 4/8, but it could well be ⅝. Am I
missing something basic?
And then the patterns is often fast changing, so it might be 4/8 at 9.00, but
could easily be 6/8 at 8.50 and 9.10, so recording a simple snapshot doesn't
fully capture the picture. I realise one has to make a cutoff at some point.
Of course this is all probably just a bit of noise in a set of records no one
is ever going to use.
Trevor
Back from the Deep South of London and Devon where it was HOT to Dundee where
it is COLD
You make a very good point, Trevor. 'Observing' the weather is pretty much a
full time job. 'Reporting' the weather by means of SYNOP or METAR observations
is, as you say, merely capturing a snapshot at a moment in time which may, or
may not, be representative of the weather experienced over a period of time.
In my time working in the Met Office at Prestwick Airport in the 1960s during
spells of bad weather ('bad' in the context of aircraft operations) we switched
to so-called 'double observing'. One observer was continually outside on the
balcony observing and recording the changes as they happened and passing this
information to the other observer who was in the observing office. The person
indoors was responsible for communicating the ever-changing information to ATC
and other interested parties. He also kept all the formal logging and
associated paperwork up to date. 'Observing' the weather at such times
therefore employed 2 people continuously. The bean counters would never allow
that today :-(
--
Norman Lynagh
Tideswell, Derbyshire
303m a.s.l.
http://peakdistrictweather.org
Twitter: @TideswellWeathr