On 07/01/2016 16:10, Norman Lynagh wrote:
On Thu, 7 Jan 2016 06:57:24 -0800 (PST), Trevor Harley
wrote:

172 mm so far this year, which while all in a day's work for Capel Curig, is extraordinary for east Scotland. And I'm sure my Davis gauge under-records.


I think most people who have a Davis AWS and a standard 5" manual raingauge find
that the Davis systematically under-reads. Mine does by a variable factor of
10-20%. I suspect that much of the variability is wind-speed related. If your
total of 172 mm is based solely on the Davis measurements then my guess is that
the true rainfall is likely to be at least 190 mm. As you say, extraordinary for
east Scotland.

Statistics published in Met.O.856c for the 30-year period 1931-1960 give the
following averages for January:

Arbroath 57 mm
Braemar 96 mm
Craibstone 78 mm
Dunbar 47 mm
Dundee 65 mm
Edinburgh 57 mm
Gordon Castle 62 mm
Marchmont 71 mm
Nairn 49 mm
Perth 70 mm
Rattray Head 36 mm
Stirling 101 mm
Wick 85 mm

These figures confirm that your measurement of 172 mm for the first few days of
January really is exceptional.


As an aside the 1981-2010 January figures I have managed to obtain for
'Edinburgh' show Royal Botanical Gdns 69mm, Gogarbank (the current
'Edinburgh' I believe - it's near the airport, 76mm), and Penicuik,
which is probably more representative of where I am, 100mm.

Whatever, I have noticed that rainfall totals are highly variable in
areas such as this and the January rainfall thus far is a mere 17mm.
Less than 10% of Trevor's deluge.


--
George in Swanston, Edinburgh, 580'asl
www.swanstonweather.co.uk
www.eppingweather.co.uk
www.winter1947.co.uk