"Robin Nicholson" wrote in
message ...
On Sat, 23 Sep 2006 01:22:40 +0100, "Philip Eden"
philipATweatherHYPHENukDOTcom wrote:

Robin, if that puts you a few km SE of Shaftesbury, your 1941-70
mean annual rainfall is 960mm, approx 30% more than Yeovilton's.
If you have more recent averages for Yeovilton then simply apply
a 30% blanket correction which should get you close.

Always bear in mind that AWS rain-gauges typically collect up
to 10% less rain than a standard manual gauge. Sometimes the
difference is even greater. I'd always recommend having a
manual gauge alongside an AWS one.

Thank you. I suppose I am actually 20 km SSW. Multimap gives my height
as 140m.
I guess the approx 30% more is the effect of the North Dorset hills.

Ah, I was looking at the wrong hill! Your 41-70 AAR is actually
1070mm which is 45% higher than Yeovilton. There are various
effects at work ... altitude, proximity to the Channel coast, and in
respect of Yeovilton a marked rainshadow in the lee of the various
ranges of hills which almost surround it.

Philip