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Old September 21st 10, 07:27 PM posted to uk.sci.weather
Len Wood Len Wood is offline
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Default High pressure at T240. Quiet and settled.

On Sep 21, 8:24*pm, Len Wood wrote:
On Sep 21, 6:59*pm, "Will Hand" wrote:





"Dawlish" wrote in message


...


I don't see a wet September. I have 75% confidence that high pressure
will be dominating our weather towards the end of the month.


**at T240, on Wednesday 29th September, most of the UK will be under
anticyclonic conditions, leading to quiet, dry and settled weather for
most**


A nice end to September. Dry days, some frost at night further north
and not a great deal of rain for most between now and then. No storms,
the jet to our NW, subsiding air over the UK and little evidence of
the influence of these extra-tropical depressions. The exception may
well be the far NW. That's my take on the weather at 10 days!


Are you still sure about this Paul? I'm still going for a warm and wet
Autumn BTW.
You made this prediction at the worst possible time, before extratropical
transistion of Igor where models were indicating all sorts of subtle
dynamical possibilities despite the agreement you happened to find around
this time from succesive runs. Ex Igor warm air advection west of Greenland
will undoubtedly throw up an anticyclone downstream near UK, but as always
with these systems there is a high probability of them injecting energy into
the jet which will make the high topple and/or receed east. the latter now
looks like taking place. An interesting development is that ex Igor rotates
west of Greenland and injects cold air south towards Newfoundland by
strengthening northerly flow this also accentuating the jet. I would not be
at all surprised to see a stormy end to September (at least up north).


Will
--


Will , it seems to me looking at the grib gfs forecast data, that the
strong northerlies are associated with a depression that comes bombing
out of Labrador on Saturday. Strong northerlies to the east of
Newfoundland result on Sunday. Admittedly Igor could have injected
some momentum and moisture to influence the midlatitude flow. Igor
itself heads north up the Davis Strait and dies a death by Saturday.
Igor was certainly a biggy, still a cat1 hurricane at the moment and
is shown frontal on the fax chart.

http://www.westwind.ch/?page=ukmb

Len
Wembury- Hide quoted text -

- Show quoted text -


Sorry about double posting! Short term memory is not what it used to
be!
Len