"Graham Easterling" wrote in message
...
On Monday, November 9, 2015 at 1:54:57 PM UTC, Dave Ludlow wrote:
On Mon, 9 Nov 2015 12:21:02 -0000, "Eskimo Will"
wrote:

"Graham Easterling" wrote in message
...

I think you'd also have to allow for distance from an onshore location.
(possibly a variable distance dependent on forecast wind strength?). E.g,
St
Ives is currently offshore, but as the spray cloud covers the entire
Land's
End peninsula, it makes little difference.

The sea state makes a difference to, there may be a lot of white water
from
a big ground sea, increasing the amount of spray above the wind
calculated
value. But sea state is pretty well forecast now, so building that in
would
be simple enough.

I think that's about it!
=====================

An example of how things can get over-complicated, happens all the time.
If
one is not careful one ends up with something that works over Cornwall
and
not elsewhere. Another complication would be cliff top versus sea level
sites.
KISS :-)

Not to mention estuaries, harbours and (narrow-ish) channels.

Oh, I just did!

Yes, but sea spray in the air, except in really stormy conditions, is really
limited to exposed areas. It's the big swell & ground sea
http://www.landsendweather.info/ that is really affecting visibility today,
not so much the strength of wind, which is generally only a F5, F6 over the
sea. You can get summer sea breezes of F4-5.

There is so much spray in the air over Mount's Bay, you can only just make
out the Mount from Mousehole (4 miles) yet the forecast visibility is still
excellent
http://www.metoffice.gov.uk/public/w...27?tab=fiveDay
Scilly is currently reporting 9km, where the forecast is also excellent.

Visibility should be excluded from post code forecasts, unless some attempt
is made to get it vaguely correct. To chose to ignore probably the most
important factor affecting visibility in areas near exposed Atlantic coast
is rather silly.
===============

Graham when the site specific system was set up and coded up back in 2008 it
was designed to be a "one size fits all" solution. There was no mechanism in
the code to include or exclude specific weather elements from individual
sites. I fear also that the motivation is going out of preparing site
forecasts now. One real impetus was the "5000 cities" feed to the BBC but
now the MetO will not be getting that contract there is unlikely to be much
funding for new development. Any changes are likely to come about through
improvements to the raw model data used in the post-processing system as
part of NWP development and the drive to fully automated forecasting
(barring the severe weather warning service) in the Met Office by 2020.

Will
--
http://www.lyneside.demon.co.uk/Hayt...antage_Pro.htm
Will Hand (Haytor, Devon, 1017 feet asl)
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