"Graham Easterling" wrote in message
...
On Sunday, September 4, 2016 at 11:19:53 AM UTC+1, xmetman wrote:
On Sunday, 4 September 2016 10:53:47 UTC+1, vidcapper wrote:
You might find this interesting, if a little out-of-date.

http://maps.nls.uk/geo/explore/#zoom...ers=10rain&b=1

You can switch between the old rainfall map & the modern one by using
the 'change transparency of overlay' slider.

I finally know why Capil Curig is so wet!


--

Paul Hyett, Cheltenham

Paul

I knew about this site, but had never noticed the 1881-1915 rainfall
overlay.

Of course this begs the question if we have rainfall data to produce such
a detailed map as this why do the Met Office only have a gridded data
series that extends back to 1910?

Bruce.

A detailed map doesn't necessarily equate to accuracy. The MetO produce
detailed actual and anomaly maps each month, showing rainfall in great
detail over west Cornwall for instance. But where are the actual rainfall
reports from? just Camborne & Culdrose. This can lead to some highly
inaccurate maps, especially in summer. It was the extreme inaccuracy of
these maps a few years back, that led me to realising Scilly was double
recording rainfall. It still took them nearly 6 months from the time I
reported it to correct it. The only reply I ever got was an unofficial
private one, giving the reasons for the problem, in some detail - it was
both interesting and disturbing (total lack of any reasonableness checks). I
never got an official response.

It meant that the 'actual' figure for the Penzance area, presumably computed
in some way from the Camborne & Scilly figures and a relief map, was 30% or
so high for several months.

Graham
Penzance
================

It is computed from a combination of high-res radar and observations. There
is some adjustment for high ground according to wind direction. It is the
radar that will be the main source of errors. There have been a few
occasions recently of radar over-estimating rainfall in my locality. It gets
worse when Predanack goes AWOL. A far better map is produced in slow time in
collaboration with the EA using many more gauges, but that is not for public
consumption - sorry.

Will
--
" Some sects believe that the world was created 5000 years ago. Another sect
believes that it was created in 1910 "
http://www.lyneside.demon.co.uk/Hayt...antage_Pro.htm
Will Hand (Haytor, Devon, 1017 feet asl)
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