On Jul 4, 4:44*pm, Graham P Davis wrote:
On Mon, 04 Jul 2011 06:36:42 -0700, Dawlish wrote:
http://www.climate-uk.com/monthly/1106.htm
How did all those forecasters and agencies miss this? I haven't seen a
single attempt at an explanation, on here, or in the press, of why any
of them were so hoplessly incorrect about the first month of this
summer.
The only reason I can come up with for them saying that June (and I know
the summer has 2 months to run, but AFAIK, they all made reference to
June being warm and dry) was going to be warm and dry was that when they
put their forecasts together, it was warm and dry in their back garden
and on the charts out to 16 days.
I have a sneaky suspicion that model output guides the first part of
most of these forecasts and the rest, past 16 days is determined by
nothing more than continued persistence from what is shown in the models
and then pure guesswork as to when the pattern may, or may not change.
The fact that no individual, or agency can demonstrate any reasonable
success and the MetO have abandoned public inquests into their seasonal
forecasts by stopping their issue, would support that assertion. Is that
assessment of the current state of seasonal forecasting wrong?
The Netweather summer forecast seems to have relied mainly on a cold SST
pool in mid-Atlantic in early May staying put. Unfortunately for their
forecast, towards the end of May, this cold pool was sliced in two by a
tongue of warm water leading to a zonal instead of meridional pattern.
Can't blame Netweather for not getting the SST F/C correct as NCEP
continued with a cold pool in the area for another year.
SST anomalies can persist with little change for several months but they
can sometimes suffer abrupt changes. My suspicion is that they are more
prone to these sudden changes in late spring and autumn. If that's true,
we're probably stuck with this zonal pattern until well into November. I
think that's also about the time when La Nina is forecast to resume.
Mind you, that's NCEP forecast so . . .
--
Graham Davis, Bracknell
Whilst it's true that money can't buy you happiness, at least you can
be miserable in comfort.
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True. The predictive model output mean shows continuing ENSO neutral
conditions, though the NOAA model predicts a double-dip La Nina.
http://www.cpc.ncep.noaa.gov/product...-fcsts-web.pdf
(Slide 27)
It changes weekly and as you can see by the model spread, there's
little agreement on exactly what will happen. It's a good example of
the difficulties of medium/longer term forecasting - of SSTs, as well
as of weather. The various agencies just cannot agree on what the
temperature of the equatorial Pacific will be, 6 months down the line.
It really is that difficult, yet some people and agencies want others
to believe in their forecasts and in their forecasting prowess. It's
absurd, in my view, but it is potentially lucrative, for some, if they
can persuade people that they know what they are talking about by
getting a forecast correct every now and then.
The Aussie BOM has stated before in it's "Wrap-ups" that ENSO
forecasts are at their least trustworthy in Spring, Graham, but by
Autumn, they feel that predictability increases. Their site is really
excellent:
http://www.bom.gov.au/climate/enso/