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Old October 13th 09, 03:40 PM posted to uk.sci.weather
Dawlish Dawlish is offline
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First recorded activity by Weather-Banter: Mar 2008
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Default High pressure and October warmth following the blow?

On Oct 3, 9:17*am, Dawlish wrote:
On Oct 2, 11:45*pm, "Ned" wrote:



LOL you live in cuckoo land. Why should we bench forecasters (and any
others) watch your posts? *We have all the access to the models we need and
we make forecasts 4 times a day, rather then the once in a blue moon pseudo
"forecast" you come up with.



**At T240 on Tuesday 13th October, pressure over the bulk of the UK
will be higher than average. These anticyclonic conditions, combined
with lower pressure to the west of Europe will advect some warm air
and daytime temperatures will be significantly above average for many
parts of the UK.**


Like I said, 10 days ago, I thought there was a clear signal and the
high pressure duly developed. Nowhere in the UK has below 1020mb at
present. As I said 5 days ago; by then it wasn't a question of whether
the high would develop, but exactly where. As it turned out, it's
location is about 250 miles further SW than the models were predicting
at the time. Hence, temperatures are a little below what I thought
they might be, as the warmest of the southerly flow is a little
further to our west, but we are getting some advection of mT air
around the high. Not a perfect forecast, but good enough at 10 days
for a correct one. Anticyclonic, settled and generally warm daytime
conditions are being experienced across the bulk of the UK.

Since I issued this 10-day forecast, there has not been a time when
there has been enough consistency in the gfs, or agreement with the
ECM for another forecast. Any forecasting at 10 days done during this
period would have been subject to a lot of doubt and watching the
switching and changing of this period within the 6-15 MetO forecast
(as far as is possible) has backed that view. The present model output
at T240 shows that perfectly. If I'd have forecast a full breakdown in
this high pressure, at any time over the last 2+ days - and that has
been shown on both models and the GEM model over the last 60 hours -
I'd have only been going with the ECM and that would have been to long
odds for 75%+ accuracy. Now the ECM is showing signs of extending the
high pressure into the last third of October.

That shows just how dificult it is to get any measure of success,
forecasting at 10 days.