Mike - I would like to come back and reply to some of the points you have made.
Mike, you can't bunch "all" long-range forecasts in a bag and say they are all dreadfully
inaccurate. Also, to put Bill Giles and my forecast in the same category is also wrong.
Bill Giles uses a sequential method of forecasting - ie. he needs to know the latest
analysis in order to project into the future. I don't. I go directly to the date I
require. Furthermore, Bill Giles explains much about the likely atmospheric weather. I
don't. My interest lies in forecasting the expected pressure situation. Your statement
reminds me of something a friend once said. He said, Long-range forecasting cannot be
done, therefore it is not done. And if you think about it, it is the death knell of all
scientific advancement.
I raised your point about my discrepancies for the 5th December. I likened them to the
discrepancies which occurred after 5 days with the NWP. I was interested to know if you used
double standards on occasions such as this. You sidestepped the argument and said that the
NWP had forecast the HP very well and had signalled it MANY days ago. Mike, I checked
with my files and the HP build up over Britain on 4th December was signalled not on the 27th
November, but on 28th November. That is 6 days before the event. And my forecasts are
inaccurate because I didn't pick up the HP at its start on 4th December, only after the 4th,
- and that at 20 or more days out. Isn't that a case of double standards.
I asked you how much leeway you would give for a forecast more than 20 days out. You
couldn't miss it, it was in capitals. You never picked up the question and you didn't give
an answer. I would say that means - no leeway. . So that means I have to be as good as
an NWP. Sounds stupid doesn't it.
Mike, this discussion can't go on. I have never been out to convince you on anything. I
have objected to your generalization, your confident way of decrying everything to do
with my long range forecast when you haven't even studied them and your setting of double
sstandards.
I have to say, too, that I respect your point of view. The forecast could be better on
some occasions. I have to thank you for your criticism (there are some people who lash out
before hand, but are as meek as a kitten after the event) and if you agree, we'll call it a
day.
Thanks again, Mike, and regards
Cheers, Keith
Mike Tullett schrieb:
On Fri, 05 Dec 2003 19:42:54 +0100, Keith Darlington wrote in
Mike, if I understand you correctly you think the detailed forecasts have a dreadful
record and you quote the detailed forecast for 5th Decamber to support your viewpoint.
Keith - I was referring to *all* those who attempt detailed forecasts at
long time ranges and there I include the likes of Bill Giles. It wasn't
aimed solely at yours.
big snip
If you find the discrepancies on the 5th December so grave, what is your opinion of
the NWP after 5 days. Are they held in the same relationship?
NWP can be quite mixed at that range (as they can be even at 24 hours).
The current build of pressure was very well signalled many days ago by
them, mind you.
Mike, I have done almost two months of forecasts. I have only found one day on which I
would say - completely wrong; not a single likeness. And I'd have a look to see why
that single forecast went wrong, and I wouldn't settle until I had found out the
reason. The date was 4th December. I didn't get the HP building up from the SW.
I saw the single depression near Spain having a connection with the Iceland LP. This
wasn't the case. I saw this coming a few days before, and I felt that if criticism
was to come, that would be the sticking point. You never noticed it, Mike, And that
tells me really how much you are studying the detailed forecasts.
I admit I don't study every day in your forecast, but I highlighted today's
as your post to Will reminded me to check what it was. I still would say
there is little relationship between your forecast for today and what has
transpired. Yes now you remind me, looking back to the 4th there was a
similar discrepancy.
For tomorrow - Saturday - you wrote:
"On 6th December, the HP of yesterday lies from S to N along the S and E
side of Britain. An Atlantic LP extends E'wards into W Scotland
Winds will be light in the E and SE of the country but will turn S and
SW later. The fine weather along the E side of the country will move off
E'wards as rain and showers take over from the W."
I see a High of 1038 mb over the north of Scotland with winds from the E
and NE over central and southern areas. You mention a low extending into W
Scotland. I see three lows on the latest UKMO charts and the nearest is
over 1000 miles away. You have fine weather in the E moving off eastwards
when tomorow's winds are bringing cloud and then a clearance *from* the
east. There may well be rain in the far SW but that will have moved from
the east as the associated fronts move west and another moves north west
from Biscay.
If you do get down to studying the forecasts, you will see that the timing of the
change-over from one situation to the next is worth while the study.
For Sunday you said:
"On 7th December, a depression lies to the N of the country. A W or
WSW airstream brings rain and showers over the N half of the
country. Slightly better weather can be found in the S."
I see a high of 1034mb over the S North Sea with the nearest (very weak)
Atlantic lows to the west of Iberia and north of the Azores. There just
isn't a low to the north of Scotland unless, by that, you include the
Barents Sea.
Sorry Keith, but I am not convinced.
--
Mike Coleraine posted to uk.sci.weather 05/12/2003 19:08:27 UTC
My aurora images here http://www.mtullett.plus.com/29a-oct and
http://www.mtullett.plus.com/20-nov/