I have been an advocate of probability forecasting on here for a few years
now. I have however been giving it some more thought and do have some
misgivings. What I have noticed in a forecast such as, say, "90% confidence
dry and mild, 10% cold and heavy snow" is that the interpretation by some of
the outcome is:-
1. If it is dry and mild then it was a good forecast.
2. If it is cold and there is heavy snow then there is the comment along
the lines "brilliant forecast, only a 10% chance and he/she was the only one
to spot it." (Not 90% inaccurate!)

This is happening to some extent, I feel, with the UKMO winter forecast. In
the overall expectation of 66% chance of being colder than average, people
that think it hasn't been that cold are saying it was good because it never
really said it would be and people that think it has been cold are saying it
was good because there was a 66% chance.

Perhaps the best option is to give a confidence in a particular forecast
with no other scenarios or their associated confidence.
(Which of course, the Met Office has in effect)
This is just some thoughts I've been having and am quite open to other
viewpoints as there is clearly more to it (or at least it's intrepretation)
than meets the eye.

Dave

Frankly, I didn't have a clue what the Met Office winter forecast
really meant. They were trying to baffle the public with
pseudo-science, made money out (that day's presentation to industry at
several hundred £££), meanwhile leaving the tabloid press with the
impression that it was going be a really bitter season.

You might just as well issue a forecast that says:
There is a 3 in 10 chance that March 2006 will be warmer than March
2005, a 3 in 10 chance that it will be colder, and a 4 in 10 chance
that it will be about the same.

Jack

wrote:
Frankly, I didn't have a clue what the Met Office winter forecast
really meant. They were trying to baffle the public with
pseudo-science, made money out (that day's presentation to industry at
several hundred £££), meanwhile leaving the tabloid press with the
impression that it was going be a really bitter season.

You might just as well issue a forecast that says:
There is a 3 in 10 chance that March 2006 will be warmer than March
2005, a 3 in 10 chance that it will be colder, and a 4 in 10 chance
that it will be about the same.

Jack

The forecast was perfectly clear to me. In effect it said "We
think it's going to be colder than recent winters but we're not too
sure". It was an honest statement and if that's "pseudoscience" give
me more of it.
The tabloid press did not get the impression that it was going
to be a "really bitter season" unless they can't read. What they did
was to say to themselves "How can we sensationalise this?" Thus the
*public* were given the impression of a severe winter. It wasn't just
the tabloids either; the Independent was as guilty as any. Whatever
the Met Office had said would have been either misunderstood or
distorted. That's the press for you. I don't know what the answer is.

Tudor Hughes, Warlingham, Surrey.

"Tudor Hughes" wrote in message Thus the*public*
were given the impression of a severe winter. It wasn't just the tabloids
either; the Independent was as guilty as any.

..... and still is as recent as this Saturday, had pictures of parts of
Europe and said of the "Siberian freeze" , "... and it's heading our way".
Of course it could still, but there was no current evidence or Met office
report to that effect.

Dave

"Tudor Hughes" wrote in message
oups.com...

The tabloid press did not get the impression that it was going
to be a "really bitter season" unless they can't read. What they did
was to say to themselves "How can we sensationalise this?" Thus the
*public* were given the impression of a severe winter. It wasn't just
the tabloids either; the Independent was as guilty as any. Whatever
the Met Office had said would have been either misunderstood or
distorted. That's the press for you. I don't know what the answer is.

Tudor Hughes, Warlingham, Surrey.

Tudor the answer is to stop buying newspapers. It's so liberating I tell you!

Will.
--

Tudor the answer is to stop buying newspapers. It's so liberating I tell you!

Will.
--

The paper I read, the Guardian, has some very good bits amongst
the froth, and I'm interested in politics and current affairs. If you
don't read the papers you may well benefit from a lower blood pressure
but you won't know what people are talking about neither will you know
what influences exist on the population at large. No good being a
hermit; there is a world out there. I may disdain much of it but I
want to know about it. And furthermore, how else are you to stop your
windscreen frosting up at night without a sheet of newspapers? The new
Berliner format of the Grauniad is useless for this - it needs two
sheets now. This is serious.

Tudor Hughes, Warlingham, Surrey.

"Tudor Hughes" wrote in message
oups.com...

wrote:
Frankly, I didn't have a clue what the Met Office winter forecast
really meant. They were trying to baffle the public with
pseudo-science, made money out (that day's presentation to industry at
several hundred £££), meanwhile leaving the tabloid press with the
impression that it was going be a really bitter season.

You might just as well issue a forecast that says:
There is a 3 in 10 chance that March 2006 will be warmer than March
2005, a 3 in 10 chance that it will be colder, and a 4 in 10 chance
that it will be about the same.

Jack

The forecast was perfectly clear to me. In effect it said "We
think it's going to be colder than recent winters but we're not too
sure". It was an honest statement and if that's "pseudoscience" give
me more of it.
The tabloid press did not get the impression that it was going
to be a "really bitter season" unless they can't read. What they did
was to say to themselves "How can we sensationalise this?" Thus the
*public* were given the impression of a severe winter. It wasn't just
the tabloids either; the Independent was as guilty as any. Whatever
the Met Office had said would have been either misunderstood or
distorted. That's the press for you. I don't know what the answer is.

Tudor Hughes, Warlingham, Surrey.


Tudor. How comes you seem to know the nature of the National press and UKMO
didn't? It must have really been a shock to them when the press exagerated
so.
Ah so naive, bless them.

Lawrence Jenkins wrote:



Tudor. How comes you seem to know the nature of the National press and
UKMO didn't? It must have really been a shock to them when the press
exagerated so.
Ah so naive, bless them.

After many years of experience of the media, the Met Office aren't being
naive, just accepting the fact that the press will get a story completely
wrong whatever you do. You just have to grin and bear it.

The media either publish un-truths because they're incompetent or they've
got an axe to grind and are lying. Sometimes it may a combination of the
two. Years ago the Times published lies about a Labour Party MP/candidate
but passed the audio tape to the BBC who broadcast it on the evening news.
It was obvious to anyone with a modicum of intelligence that the tape had
been edited to alter the meaning but the BBC never did spot it. The Times
lied but I suspect the BBC were just being plain stupid.

--
Graham Davis
Bracknell

"Graham P Davis" wrote in message

After many years of experience of the media, the Met Office aren't being
naive, just accepting the fact that the press will get a story completely
wrong whatever you do. You just have to grin and bear it.

Oh, yes? So this is why they began their first press release about the
winter
by saying:
QUOTE
A prolonged, severe winter is one of the biggest threats to the efficient
day-to-day running of the country. With this in mind, the Met Office has
given advanced warning to many of its customers ...etc
UNQUOTE
What on earth did they expect? You catch the jaded news editor's
eye in the first sentence of your press release. He doesn't read the
rest. If you accept that the chief press officer knows what he's doing
then you have to accept that this was deliberate.

Philip Eden

In message , Dave.C
writes
I have been an advocate of probability forecasting on here for a few years
now. I have however been giving it some more thought and do have some
misgivings. What I have noticed in a forecast such as, say, "90% confidence
dry and mild, 10% cold and heavy snow" is that the interpretation by some of
the outcome is:-
1. If it is dry and mild then it was a good forecast.
2. If it is cold and there is heavy snow then there is the comment along
the lines "brilliant forecast, only a 10% chance and he/she was the only one
to spot it." (Not 90% inaccurate!)

This is happening to some extent, I feel, with the UKMO winter forecast. In
the overall expectation of 66% chance of being colder than average, people
that think it hasn't been that cold are saying it was good because it never
really said it would be and people that think it has been cold are saying it
was good because there was a 66% chance.

Perhaps the best option is to give a confidence in a particular forecast
with no other scenarios or their associated confidence.
(Which of course, the Met Office has in effect)
This is just some thoughts I've been having and am quite open to other
viewpoints as there is clearly more to it (or at least it's intrepretation)
than meets the eye.

Dave

As I have said a couple of times recently a single probability forecast
cannot be judged to be either accurate or inaccurate. Accuracy, or
perhaps better described as reliability, can only be judged by
evaluating a representative sample of probability forecasts. I would
think that a minimum of something like 20 forecasts would be needed.

If an event occurred, on average, on 3 occasions out of every 4 in which
it was forecast to have a 75 percent probability of occurrence then that
probability forecasting would have been spot on.

The Met Office forecast of a 2-1 probability of a colder than average
winter cannot, on its own, be evaluated as being either accurate or
inaccurate.

Norman.
(delete "thisbit" twice to e-mail)
--
Norman Lynagh Weather Consultancy
Chalfont St Giles 85m a.s.l.
England