High pressure at T240. Quiet and settled.
 

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!

High pressure at T240. Quiet and settled.
 

On Sep 19, 9:36*pm, Dawlish wrote:
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!

Ah, but those extra-tropical storms running up the east coast of
America are basically the cause of the more settled conditions will be
experiencing in the coming week or two.

Keith (Southend)

High pressure at T240. Quiet and settled.
 

On Sun, 19 Sep 2010 at 13:36:21, Dawlish wrote in
uk.sci.weather :

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**

Preferably something nice & zonal for the week after, though...
--
Paul Hyett, Cheltenham (change 'invalid83261' to 'blueyonder' to email me)

High pressure at T240. Quiet and settled.
 

"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!

The GFS at least has been flip-flopping like mad between low & high
pressure dominated weather for the past week or so.
--
Col

Bolton, Lancashire
160m asl

High pressure at T240. Quiet and settled.
 

"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
--

High pressure at T240. Quiet and settled.
 

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
--

I'm right 80% of the time Will, over 90 different forecasts at all
times of the year. That means I will be wrong once in 5 times. I
wouldn't be surprised to see a wet end to September in the far NW
either. 2 days ago, that's what I suggested may well happen. I don't
see this as the worst possible time to forecast; that implies that
other times are easier. 5 years of doing this have shown me there are
no "easy" times and the difficult times are when we see no agreement
and no consistency. An 80% success rate shows me the system works.

Judge the forecast at outcome and not 2 days in, is what I would
always say. As it stands now, I'm less confident than I was 2 days ago
and if this forecast is one of the 20% that end up as incorrect and it
ends up a wet end to Autumn - oh well! Let's wait another 8 days
though.

To link any changes directly to a particular extra-tropical storm,
however, I feel is wrong, as evidenced by no forecastability from the
past and several tropical storms already this autumn, most of which
have appeared to have very little attributable effect and at least one
of which you said would influence our weather, but didn't seemingly
inject any energy into the jet and we ended up with quiet and settled
conditions instead.

High pressure at T240. Quiet and settled.
 

"Dawlish" wrote in message
...
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
--

I'm right 80% of the time Will, over 90 different forecasts at all
times of the year. That means I will be wrong once in 5 times. I
wouldn't be surprised to see a wet end to September in the far NW
either. 2 days ago, that's what I suggested may well happen. I don't
see this as the worst possible time to forecast; that implies that
other times are easier. 5 years of doing this have shown me there are
no "easy" times and the difficult times are when we see no agreement
and no consistency. An 80% success rate shows me the system works.

Judge the forecast at outcome and not 2 days in, is what I would
always say. As it stands now, I'm less confident than I was 2 days ago
and if this forecast is one of the 20% that end up as incorrect and it
ends up a wet end to Autumn - oh well! Let's wait another 8 days
though.

To link any changes directly to a particular extra-tropical storm,
however, I feel is wrong, as evidenced by no forecastability from the
past and several tropical storms already this autumn, most of which
have appeared to have very little attributable effect and at least one
of which you said would influence our weather, but didn't seemingly
inject any energy into the jet and we ended up with quiet and settled
conditions instead.
====================

You misunderstand Paul. All large extra-tropical storms will influence the
jet. Some will cause the jet to buckle (meridional extension) and may result
in a developing anticyclone and others will inject moisture and energy in
such a way as to make depressions more active or even help develop
downstream lows 1000 miles away like the low developing at the end of this
week, that has clear dynamical links to Igor. Technical briefings at work
have mentioned such effects for several weeks now and they are soundly based
in theory, like that paper I told you about. The fact that "outcomes" as you
put it do not appear to back up the theory is that models are not yet good
enough to model the fine interactions and dynamical processes during
extra-tropical transistion. A low going just west or just east of Greenland
is critical.

Will
--

High pressure at T240. Quiet and settled.
 

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 gfs grib forecast charts, that
Igor continues heading north up the Davis Strait and dies a death. The
strong northerlies you talk about are from a depression which comes
bombing out from Labrador on Saturday, giving strong northwesterlies
on Sunday to the east of Newfoundland. Admittedly, this depression
could well have been influenced by a momentum and moisture injection
from Igor. Igor has been a biggy and is still classed as a hurricane
cat 1 for the moment. Fax charts are showing it as frontal now.

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

Len Wood
Wembury

High pressure at T240. Quiet and settled.
 

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

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