On Sep 10, 11:02*am, Richard Dixon wrote:
On 10 Sep, 10:28, Dawlish wrote:

No Richard. The technique does not allow that and never has. If it
did, it would point to significant and consistent model accuracy at 10
days and we'd have consistently accurate forecasts from the MetO at 10
days and we don't.

Ahh right. Interesting, but doesn't this mean you're just picking and
choosing when you make a forecast? A bit like betting on the favourite
of a horse race when the odds are less than evens? Yes, I'm playing
devil's advocate here !!

Richard

No. I'm determining when a forecast is 75% likely to achieve outcome
at 10 days. Most times, it most certainly isn't; as I'm sure you and
any other forecasters would agree. Will did say that forecasting
anticyclones at this time of year is not easy and the chances of this
one developing (at 10 days out, back on Aug 31st) were no better than
50%. I didn't think that, or I wouldn't have forecast. This was one of
those instances where it was possible to have forecast this
accurately, from 10 days out.

I don't mind you playing devil's advocate. Anyone who issues any kind
of forecast should be prepared to defend both the accuracy and the
methodology. I note you aren't doubting the accuracy! *))

If you follow the earlier posts on this thread, then back on Aug
31st., the MetO were not clearly forecasting the development of such a
dominant high pressure having developed by today. So how could I have
done it? I don't have access to any tools not available to the MetO.