"Adrian D. Shaw" wrote in message
...
Philip, this confuses and surprises me somewhat:

Felly sgrifennodd Philip Eden philipATweatherHYPHENukDOTcom:
Note the use of the word "will", and the absence of any
percentage probability.

To be fair, there was a probability if you looked up the forecasting
methods, where they said that the May SST anomalies (?I think) predict
with 2/3 certainty the NAO. That's from memory, and I am open to
correction!

So why is it that the weather that has dominated here and in continental
Europe recently is exactly what one would have expected from a negative
NAO
(is it not?). It certainly matches closely what I made a point of reading
about when I saw the NAO forecast.

Let me throw another thought into the discussion. A -ve winter NAOi
does not automatically guarantee a -ve winter CET. (OK, I know that's
not quite what was offered, but it's what people are expecting). A quick
flick through the individual monthly sea-level pressure charts for the
last 30 years suggests that the relationship between NAOi and CET
may also be something like 2/3 (maybe a little more, but not much).

So, if we accept that figure, the possible outcomes a
44% colder than average with a -ve NAOi
22% colder than average with a +ve NAOi
22% warmer than average with a -ve NAOi
11% warmer than average with a +ve NAOi

So, if the forecast is right for the wrong reason, is it a success?
If it is wrong, but for the right reason, is that a success?

I can see the press release forming as I speak. Either of those will
be a "partial success" or a "qualified success". So there is an 89%
probability that the MO's winter forecast will be spun as a success
or a partial success.

Just try it, Wayne.

Philip Eden