On Sep 10, 5:07*pm, Richard Dixon wrote:
On 10 Sep, 16:53, Dawlish wrote:

Unlike dear Piers, I've always been completely open about my
methodology and it is simple.

Well fair play.

If I see 5 consecutive runs of the gfs showing a very similar set up
(consistency) and if the ECM agrees with what the gfs is showing,
there is a 75% likelihood of an event occurring. Without either of
those two criteria being reached, I would not forecast. In doing what
I have done, I know that the knack is knowing when NOT to forecast.

Is this specific weather types - i.e. a cold easterly or a high
pressure or does this include very short-wave features? Have you had
any luck prediction, for example, a day with a severe gale 10 days
ahead? It would be interesting to see what sort of weather type the
75% of the successes are, and what weather types the 25% of failures
are and whether the two populations are specifically different. Now
I'm assuming that Hurricane Bill in the mid-Atlantic was classed as a
failure? The GFS and the EC had a tight-cored low for several runs and
that didn't come off in the end.

Try it; simple methodology, pretty accurate outcomes. Then it just
takes a nerdy kind of nature to watch almost every single gfs and ECM
run for nearly 4 years to test it over time and a very thick skin to
deal with the criticism when a forecast goes very wrong from the same
people that wouldn't dream of giving praise when a forecast turns out
correct.

That should only really happen if you crow too much when it is right
(see P. Corbyn, 1990-2009) and people want to put you in your place!
If I had the chance to change your method I'd be looking for ECMWF
first and then GFS second (third...fourth?) !

I can assure you that Internet vultures are a far more
discerning panel of judges than any peer-reviewed journal!! Their
silence is approbation enough.

Judges should be fair unless you've upset them !!

Richard

Heh! LOL!

I didn't forecast anything about ex-Hurricane Bill. There was nothing
like enough agreement at 10 days - remember Bill was still tropical 10
days before and its path was by no means predictable, though the
models did a fair job at that range, with a hurricane whose movements
are often notoriously difficult to predict, even at 24-72 hours.

The last time I issued a 10 day forecast using this methodology was on
the 6th June for the 16th, saying that high pressure would be in
charge. It was wrong. Over the summer, there have been no occasions
that I have seen where agreement and consistency have occurred, Hence;
no forecasts - mind you, like I said, I've been mainly looking for
changes of pattern and what changes there have been came under my 10-
day radar and were not showing at T240.