There's a yellow snow warning in force for here from 1800 this evening till
1000 on Saturday. The current automated forecast for Tideswell gives the
following:

Fri 10th
--------
1800: Cloudy. Probability of precipitation 10%
1900: Cloudy. PoP 10%
2000: Cloudy. PoP 10%
2100: Partly cloudy. PoP 5%
2200: Slight snow. PoP 50%
2300: Cloudy. PoP 10%

Sat 11th
--------
0000: Cloudy. PoP 10%
0100: Cloudy. PoP 10%
0200: Slight snow. PoP 50%
0300: Slight snow. PoP 60%
0400: Slight snow. PoP 70%
0500: Heavy snow. PoP 90%
0600: Heavy snow. PoP 80%
0700: Slight snow. PoP 60%
0800: Slight snow. PoP 60%
0900: Slight snow. PoP 60%
1000: Slight snow. PoP 60%

That takes us to the end of the period of validity of the yellow warning. Yet,
after that the Tideswell forecast has slight snow continuing till 1300 then it
predicts heavy snow from 1400 on Saturday right through to 1500 on Sunday, with
no current warning in force for this.

So, we have a warning for a 16-hour period during which not much snow is
forecast to fall then a forecast of 24 hours of heavy snow for which no warning
has been issued. It doesn't hang together very well :-(

--
Norman Lynagh
Tideswell, Derbyshire
303m a.s.l.
http://peakdistrictweather.org
@TideswellWeathr

On 10 Feb 2017 19:03:11 GMT
"Norman Lynagh" wrote:

There's a yellow snow warning in force for here from 1800 this evening till
1000 on Saturday. The current automated forecast for Tideswell gives the
following:

Fri 10th
--------
1800: Cloudy. Probability of precipitation 10%
1900: Cloudy. PoP 10%
2000: Cloudy. PoP 10%
2100: Partly cloudy. PoP 5%
2200: Slight snow. PoP 50%
2300: Cloudy. PoP 10%

Sat 11th
--------
0000: Cloudy. PoP 10%
0100: Cloudy. PoP 10%
0200: Slight snow. PoP 50%
0300: Slight snow. PoP 60%
0400: Slight snow. PoP 70%
0500: Heavy snow. PoP 90%
0600: Heavy snow. PoP 80%
0700: Slight snow. PoP 60%
0800: Slight snow. PoP 60%
0900: Slight snow. PoP 60%
1000: Slight snow. PoP 60%

That takes us to the end of the period of validity of the yellow warning. Yet,
after that the Tideswell forecast has slight snow continuing till 1300 then it
predicts heavy snow from 1400 on Saturday right through to 1500 on Sunday,
with no current warning in force for this.

So, we have a warning for a 16-hour period during which not much snow is
forecast to fall then a forecast of 24 hours of heavy snow for which no
warning has been issued. It doesn't hang together very well :-(


Produced by two different methods. I suspect the human Chief Forecaster is not
aware of the automated forecast. I agree it's an utter shambles and a disgrace.

Will
--

Will Hand wrote:

On 10 Feb 2017 19:03:11 GMT
"Norman Lynagh" wrote:

There's a yellow snow warning in force for here from 1800 this evening till
1000 on Saturday. The current automated forecast for Tideswell gives the
following:

Fri 10th
--------
1800: Cloudy. Probability of precipitation 10%
1900: Cloudy. PoP 10%
2000: Cloudy. PoP 10%
2100: Partly cloudy. PoP 5%
2200: Slight snow. PoP 50%
2300: Cloudy. PoP 10%

Sat 11th
--------
0000: Cloudy. PoP 10%
0100: Cloudy. PoP 10%
0200: Slight snow. PoP 50%
0300: Slight snow. PoP 60%
0400: Slight snow. PoP 70%
0500: Heavy snow. PoP 90%
0600: Heavy snow. PoP 80%
0700: Slight snow. PoP 60%
0800: Slight snow. PoP 60%
0900: Slight snow. PoP 60%
1000: Slight snow. PoP 60%

That takes us to the end of the period of validity of the yellow warning.
Yet, after that the Tideswell forecast has slight snow continuing till 1300
then it predicts heavy snow from 1400 on Saturday right through to 1500 on
Sunday, with no current warning in force for this.

So, we have a warning for a 16-hour period during which not much snow is
forecast to fall then a forecast of 24 hours of heavy snow for which no
warning has been issued. It doesn't hang together very well :-(


Produced by two different methods. I suspect the human Chief Forecaster is not
aware of the automated forecast. I agree it's an utter shambles and a
disgrace.

Will

This then raises the question: If the Chief Forecaster does not slavishly
follow the machine output then why is the machine output considered to be
satisfactory end-user material? That brings me back to the opinion that I have
aired on here recently i.e. that numerical model output is a tool to be used by
experienced forecasters to assist them in their decision-making. It is not
reliable enough to be issued as an end-user product. It is not fit for that
purpose. The sort of conflicts that I have highlighted above lay the Met Office
wide open to possible legal action from someone who suffers a loss resulting
from relying on a product which tells a different story from the 'party line'
story. Getting the forecast wrong is one thing but having 2 conflicting
forecasts valid concurrently is quite another.

--
Norman Lynagh
Tideswell, Derbyshire
303m a.s.l.
http://peakdistrictweather.org
@TideswellWeathr

"Norman Lynagh" wrote in message
...
Will Hand wrote:

On 10 Feb 2017 19:03:11 GMT
"Norman Lynagh" wrote:

There's a yellow snow warning in force for here from 1800 this evening
till
1000 on Saturday. The current automated forecast for Tideswell gives
the
following:

Fri 10th
--------
1800: Cloudy. Probability of precipitation 10%
1900: Cloudy. PoP 10%
2000: Cloudy. PoP 10%
2100: Partly cloudy. PoP 5%
2200: Slight snow. PoP 50%
2300: Cloudy. PoP 10%

Sat 11th
--------
0000: Cloudy. PoP 10%
0100: Cloudy. PoP 10%
0200: Slight snow. PoP 50%
0300: Slight snow. PoP 60%
0400: Slight snow. PoP 70%
0500: Heavy snow. PoP 90%
0600: Heavy snow. PoP 80%
0700: Slight snow. PoP 60%
0800: Slight snow. PoP 60%
0900: Slight snow. PoP 60%
1000: Slight snow. PoP 60%

That takes us to the end of the period of validity of the yellow
warning.
Yet, after that the Tideswell forecast has slight snow continuing till
1300
then it predicts heavy snow from 1400 on Saturday right through to 1500
on
Sunday, with no current warning in force for this.

So, we have a warning for a 16-hour period during which not much snow
is
forecast to fall then a forecast of 24 hours of heavy snow for which no
warning has been issued. It doesn't hang together very well :-(


Produced by two different methods. I suspect the human Chief Forecaster
is not
aware of the automated forecast. I agree it's an utter shambles and a
disgrace.

Will

This then raises the question: If the Chief Forecaster does not slavishly
follow the machine output then why is the machine output considered to be
satisfactory end-user material? That brings me back to the opinion that I
have
aired on here recently i.e. that numerical model output is a tool to be
used by
experienced forecasters to assist them in their decision-making. It is not
reliable enough to be issued as an end-user product. It is not fit for
that
purpose. The sort of conflicts that I have highlighted above lay the Met
Office
wide open to possible legal action from someone who suffers a loss
resulting
from relying on a product which tells a different story from the 'party
line'
story. Getting the forecast wrong is one thing but having 2 conflicting
forecasts valid concurrently is quite another.


Oh dear where do we start. First of all the main driver for post-code
specific auto forecasts were the commercial people back in the early
noughties. This was backed up by a committee called the public weather
service customer group. NWP scientists were sceptical but were nevertheless
tasked with providing products. Around circa 2008 it was realised that
conflicts as you have highlighted could occur, so two strategic strands were
set in motion. One was full automation by 2020 (apart from warnings) and the
other was something called "Strategic Intervention" (SI). The idea of SI was
that the Chief forecasters would modify all NWP products once before they
left the building for customers. That way there would be one story and only
one story. But very soon massive technical problems became apparent. What do
we do with ensembles, how do you do the intervention? Do you modify surface
fields and use Omega equation ideas to do the rest automatically and how on
earth do you modify cloud/precip. etc etc. As well as these issues there
were also IT infrastructure problems, how do you interface the NWP with the
forecaster in a way that he could alter it quickly and efficiently? Then
there was the big issue of who was to pay for it? As far as I am aware SI
was scrapped. The big white hope is now high res. NWP and full automation
using a high resolution ensemble approach.

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)
---------------------------------------------

On 10/02/17 21:20, Eskimo Will wrote:

"Norman Lynagh" wrote in message
...
Will Hand wrote:

On 10 Feb 2017 19:03:11 GMT
"Norman Lynagh" wrote:

There's a yellow snow warning in force for here from 1800 this
evening till
1000 on Saturday. The current automated forecast for Tideswell
gives the
following:

Fri 10th
--------
1800: Cloudy. Probability of precipitation 10%
1900: Cloudy. PoP 10%
2000: Cloudy. PoP 10%
2100: Partly cloudy. PoP 5%
2200: Slight snow. PoP 50%
2300: Cloudy. PoP 10%

Sat 11th
--------
0000: Cloudy. PoP 10%
0100: Cloudy. PoP 10%
0200: Slight snow. PoP 50%
0300: Slight snow. PoP 60%
0400: Slight snow. PoP 70%
0500: Heavy snow. PoP 90%
0600: Heavy snow. PoP 80%
0700: Slight snow. PoP 60%
0800: Slight snow. PoP 60%
0900: Slight snow. PoP 60%
1000: Slight snow. PoP 60%

That takes us to the end of the period of validity of the yellow
warning.
Yet, after that the Tideswell forecast has slight snow continuing
till 1300
then it predicts heavy snow from 1400 on Saturday right through to
1500 on
Sunday, with no current warning in force for this.

So, we have a warning for a 16-hour period during which not much
snow is
forecast to fall then a forecast of 24 hours of heavy snow for
which no
warning has been issued. It doesn't hang together very well :-(


Produced by two different methods. I suspect the human Chief
Forecaster is not
aware of the automated forecast. I agree it's an utter shambles and a
disgrace.

Will

This then raises the question: If the Chief Forecaster does not
slavishly
follow the machine output then why is the machine output considered to be
satisfactory end-user material? That brings me back to the opinion
that I have
aired on here recently i.e. that numerical model output is a tool to
be used by
experienced forecasters to assist them in their decision-making. It is
not
reliable enough to be issued as an end-user product. It is not fit for
that
purpose. The sort of conflicts that I have highlighted above lay the
Met Office
wide open to possible legal action from someone who suffers a loss
resulting
from relying on a product which tells a different story from the
'party line'
story. Getting the forecast wrong is one thing but having 2 conflicting
forecasts valid concurrently is quite another.


Oh dear where do we start. First of all the main driver for post-code
specific auto forecasts were the commercial people back in the early
noughties. This was backed up by a committee called the public weather
service customer group. NWP scientists were sceptical but were
nevertheless tasked with providing products. Around circa 2008 it was
realised that conflicts as you have highlighted could occur, so two
strategic strands were set in motion. One was full automation by 2020
(apart from warnings) and the other was something called "Strategic
Intervention" (SI). The idea of SI was that the Chief forecasters would
modify all NWP products once before they left the building for
customers. That way there would be one story and only one story. But
very soon massive technical problems became apparent. What do we do with
ensembles, how do you do the intervention? Do you modify surface fields
and use Omega equation ideas to do the rest automatically and how on
earth do you modify cloud/precip. etc etc. As well as these issues there
were also IT infrastructure problems, how do you interface the NWP with
the forecaster in a way that he could alter it quickly and efficiently?
Then there was the big issue of who was to pay for it? As far as I am
aware SI was scrapped. The big white hope is now high res. NWP and full
automation using a high resolution ensemble approach.

Will

That's all very well, Will, but you've got the timing wrong. 2008 was
four years after I retired and yet I remember the idea of 'SI' being
insisted on and that I was the one who pointed out the problems you
mention above. Many times.

As far as I recall at the moment, the idea was raised near the end of
the last century. Give me a while and I'll try and clear out the cobwebs
from my mind palace and come up with a few more details.

--
Graham P Davis, Bracknell, Berks. [Retd meteorologist/programmer]
Web-site: http://www.scarlet-jade.com/
There are more fools than knaves in the world, else the knaves would
not have enough to live upon. [Samuel Butler]

"Will Hand" wrote in message
. ..
On 10 Feb 2017 19:03:11 GMT
"Norman Lynagh" wrote:

There's a yellow snow warning in force for here from 1800 this evening
till
1000 on Saturday. The current automated forecast for Tideswell gives the
following:

Fri 10th
--------
1800: Cloudy. Probability of precipitation 10%
1900: Cloudy. PoP 10%
2000: Cloudy. PoP 10%
2100: Partly cloudy. PoP 5%
2200: Slight snow. PoP 50%
2300: Cloudy. PoP 10%

Sat 11th
--------
0000: Cloudy. PoP 10%
0100: Cloudy. PoP 10%
0200: Slight snow. PoP 50%
0300: Slight snow. PoP 60%
0400: Slight snow. PoP 70%
0500: Heavy snow. PoP 90%
0600: Heavy snow. PoP 80%
0700: Slight snow. PoP 60%
0800: Slight snow. PoP 60%
0900: Slight snow. PoP 60%
1000: Slight snow. PoP 60%

That takes us to the end of the period of validity of the yellow warning.
Yet,
after that the Tideswell forecast has slight snow continuing till 1300
then it
predicts heavy snow from 1400 on Saturday right through to 1500 on
Sunday,
with no current warning in force for this.

So, we have a warning for a 16-hour period during which not much snow is
forecast to fall then a forecast of 24 hours of heavy snow for which no
warning has been issued. It doesn't hang together very well :-(


Produced by two different methods. I suspect the human Chief Forecaster is
not
aware of the automated forecast. I agree it's an utter shambles and a
disgrace.


And here's a link to give an idea of what SI was about.
http://ri.search.yahoo.com/_ylt=A7x9...fQkfcxjouwS0Y-

And just google "strategic intervention met office" for more public
documents.

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)
---------------------------------------------

On 10/02/17 21:37, Eskimo Will wrote:

And here's a link to give an idea of what SI was about.
http://ri.search.yahoo.com/_ylt=A7x9...fQkfcxjouwS0Y-


That's a 'Forbidden Link', Will. Could you please give us the real link
instead of the Yahoo search? Perhaps that will be accessible?

--
Graham P Davis, Bracknell, Berks. [Retd meteorologist/programmer]
Web-site: http://www.scarlet-jade.com/
There are more fools than knaves in the world, else the knaves would
not have enough to live upon. [Samuel Butler]

Will Hand wrote:

On 10 Feb 2017 19:03:11 GMT
"Norman Lynagh" wrote:

There's a yellow snow warning in force for here from 1800 this evening till
1000 on Saturday. The current automated forecast for Tideswell gives the
following:

Fri 10th
--------
1800: Cloudy. Probability of precipitation 10%
1900: Cloudy. PoP 10%
2000: Cloudy. PoP 10%
2100: Partly cloudy. PoP 5%
2200: Slight snow. PoP 50%
2300: Cloudy. PoP 10%

Sat 11th
--------
0000: Cloudy. PoP 10%
0100: Cloudy. PoP 10%
0200: Slight snow. PoP 50%
0300: Slight snow. PoP 60%
0400: Slight snow. PoP 70%
0500: Heavy snow. PoP 90%
0600: Heavy snow. PoP 80%
0700: Slight snow. PoP 60%
0800: Slight snow. PoP 60%
0900: Slight snow. PoP 60%
1000: Slight snow. PoP 60%

That takes us to the end of the period of validity of the yellow warning.
Yet, after that the Tideswell forecast has slight snow continuing till 1300
then it predicts heavy snow from 1400 on Saturday right through to 1500 on
Sunday, with no current warning in force for this.

So, we have a warning for a 16-hour period during which not much snow is
forecast to fall then a forecast of 24 hours of heavy snow for which no
warning has been issued. It doesn't hang together very well :-(


Produced by two different methods. I suspect the human Chief Forecaster is not
aware of the automated forecast. I agree it's an utter shambles and a
disgrace.

Will

The warnings have just caught up with the forecasts. Yellow snow warning issued
at 1050 this morning, valid from 2100 this evening till 1500 tomorrow. The snow
is heavier now than it was at any time during the previous warning period that
expired at 1000 today. I suppose we have white snow at the moment, not yellow
snow :-)

--
Norman Lynagh
Tideswell, Derbyshire
303m a.s.l.
http://peakdistrictweather.org
@TideswellWeathr