"Graham Easterling" wrote in message
...
On Monday, November 9, 2015 at 10:38:50 AM UTC,
wrote:
"Richard Dixon" wrote in message
...
On Monday, 9 November 2015 10:11:35 UTC,
wrote:

As you say Graham easily fixed with a couple of lines of FORTRAN
...
IF (WINDSPEED spray_threshold .AND. onshore_flag) SPRAY = .TRUE.
...
IF (SPRAY) then VIS = moderate

Wouldn't you need a directional component for spray, Will - i.e. one
that
carries the water inland? Or is that the onshore_flag bit?


In the site specific (best data) forecast code there is a flag for each
site
that is switched on if the wind is onshore (it is already used for the
temperature forecasts and a few other things).

Please note: I have changed variable names to protect code integrity which
is actually Crown Copyright.


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 :-)

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