02/01/2008 09:21:58
Paul Hyett wrote in message


In uk.sci.weather on Tue, 1 Jan 2008, Philip Eden
wrote :
"John Hall" wrote:
Philip Eden writes:

Sunshine totals ranged from 89.0h at East Malling (Kent) -
presumed KZ sensor - to 25.5h at Lerwick (KZ sensor).

Percentages ranged from 239 at Kirkwall (Orkney)
to 68 at Watnall (Notts)

A low sunshine total at Lerwick and a very high percentage at
Kirkwall
seems like an unlikely combination. Could one figure or the
other be in
error?
--
No, John ... the Lerwick figure, although the smallest in the
country, was
still 175% of the local average! They don't get much sunshine that
far
north in December ...

Plugging their latitude into my sunrise/sunset calculator, they
only get
5h45m of daylight in midwinter!
--
Paul Hyett, Cheltenham (change 'invalid83261' to 'blueyonder' to
email me)
December 2007 sunshine total for Fair Isle is a staggering 43.1 hours.
246.2% based on the 1976-2001 average of just 17.5 hours.
A couple of extra 'sunny' days can make an enourmous % difference. At
this lattitude a relatively clear sky can yield almost no recirdable
sunshine if the small amount of cloud present sits along the southern
horizon - the worse culprit being frontal cloud with CBs in an
unstable NW'ly following a close second.
Interesting pressure range on Fair Isle December 2007. 970.1hPa 0130z
7th December to 1041.7hPa between 2315-2355z on the 17th.
Dave, Fair Isle