The current forecast for Penzance is excellent. It is mostly moderate, occasionally good in shelter, simply because there is so much sea spray in the air. https://www.minack.com/a-living-theatre/webcams/

I know sea spray isn't taken into account, but it's a pretty easy parameter to forecast. Obviously too much effort for the MetO who prefer visibility forecasts to be wrong in Atlantic locations most of the winter. I've been told there are no plans to introduce sea spray as a factor, I mean why bother wth Nowheresville. Why bother with mist then?

Yesterday saw a maximum of 15.3C, meaning every day this month has exceeded 15C. Previously, the maximum number of days exceeding 15C in November was 7 in 2011.

Graham
Penzance

On Monday, 9 November 2015 09:21:48 UTC, Graham Easterling wrote:
The current forecast for Penzance is excellent. It is mostly moderate, occasionally good in shelter, simply because there is so much sea spray in the air. https://www.minack.com/a-living-theatre/webcams/

I know sea spray isn't taken into account, but it's a pretty easy parameter to forecast. Obviously too much effort for the MetO who prefer visibility forecasts to be wrong in Atlantic locations most of the winter. I've been told there are no plans to introduce sea spray as a factor, I mean why bother wth Nowheresville. Why bother with mist then?

Yesterday saw a maximum of 15.3C, meaning every day this month has exceeded 15C. Previously, the maximum number of days exceeding 15C in November was 7 in 2011.

Graham
Penzance
--------------------------------------------------------------------------------
But Graham. I have been down your way and got soaked by sea spray while walking by the sea.
Most unpleasant.
You don't want them forecasting that do you?
Best to keep quiet about it.
It would put the holidaymakers off from coming.

Len
Wembury

"Graham Easterling" wrote in message
...
The current forecast for Penzance is excellent. It is mostly moderate,
occasionally good in shelter, simply because there is so much sea spray in
the air. https://www.minack.com/a-living-theatre/webcams/

I know sea spray isn't taken into account, but it's a pretty easy parameter
to forecast. Obviously too much effort for the MetO who prefer visibility
forecasts to be wrong in Atlantic locations most of the winter. I've been
told there are no plans to introduce sea spray as a factor, I mean why
bother wth Nowheresville. Why bother with mist then?
========================

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
....

If I still worked there I could easily get into the code, make a few private
changes and test it, but I'm not so you will have to contact the MetO.

Visibility is presently worked out using an over-complicated formula (left
over from 1990s) involving liquid water content, a more pragmatic soultion
would imo be better but would not be as rigorous of course. This is where
private met. companies score as pragmatism can often be better or at least
as good as rigour.

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

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?

Richard

"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.

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

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.

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

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!

Graham
Penzance

"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)
---------------------------------------------

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!

--
Dave
Fareham (W)

On Monday, 9 November 2015 13:54:57 UTC, Dave Ludlow wrote:
On Mon, 9 Nov 2015 12:21:02 -0000, "Eskimo Will"
wrote:

"Graham Easterling" rote 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!

--
Dave
Fareham (W)
---------------------------------------------------------------------------
And what about my garden and windows?
Not sure a spray forecast would help me.
Although I could have a bucket of water ready for when the wind died down.

Len
Wembury 1 km from sea at 83 m asl.

-------------------------------------------------------------------------------

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!

--
Dave
Fareham (W)

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
Penzance