The question I keep asking myself is what has caused/is causing this
pattern change? We know the jet stream buckling and doing some odd
things to cause the blocking, but what set it off.?
--
Keith (Southend)
http://www.southendweather.net
e-mail: kreh at southendweather dot net

"Keith(Southend)" wrote in message
...
The question I keep asking myself is what has caused/is causing this
pattern change? We know the jet stream buckling and doing some odd things
to cause the blocking, but what set it off.?

Keith, not really sure but these things are often triggered by events in the
stratosphere.

Many many years ago some 'old lag' forecasters used to swear by the 100 mb
charts for spotting changes over a week ahead in the days before GFS, ECM
etc.

Will
--

On Dec 9, 10:53*pm, "Will Hand" wrote:
"Keith(Southend)" wrote in message

...

The question I keep asking myself is what has caused/is causing this
pattern change? We know the jet stream buckling and doing some odd things
to cause the blocking, but what set it off.?

Keith, not really sure but these things are often triggered by events in the
stratosphere.

Many many years ago some 'old lag' forecasters used to swear by the 100 mb
charts for spotting changes over a week ahead in the days before GFS, ECM
etc.

Will
--

Gosh Will. You are not going to like this but you can getting close to
Piers-type talk. Solar activity affecting the high atmosphere,
lowering ozone concentrations, therefore producing a cooling,
subsidence, and high pressure at the surface....

A trigger indeed!

Len Wood

"Keith(Southend)" wrote in message
...
The question I keep asking myself is what has caused/is causing this
pattern change? We know the jet stream buckling and doing some odd things
to cause the blocking, but what set it off.?
--
Keith (Southend)
http://www.southendweather.net
e-mail: kreh at southendweather dot net


It's the planet lurching into a cooling phase-a new Heinrich Event. This of
course is unlike the heimlich manoeuvre which the delegates in Copenhagen
will need when they choke on their caviar as they see the snow piling up
outside the hotels and conference halls .

By the way Dawlish I have taken a few liberties here for effect.

On Wed, 9 Dec 2009 at 22:25:39, "Keith(Southend)"
wrote in uk.sci.weather :

The question I keep asking myself is what has caused/is causing this
pattern change? We know the jet stream buckling and doing some odd
things to cause the blocking, but what set it off.?

Must be those damned butterflies again...
--
Paul Hyett, Cheltenham (change 'invalid83261' to 'blueyonder' to email me)

Keith(Southend) wrote:

The question I keep asking myself is what has caused/is causing this
pattern change? We know the jet stream buckling and doing some odd
things to cause the blocking, but what set it off.?

Cold SST pool near 40N 40W seems to me to be the most likely candidate. That
causes a high pressure anomaly near Iceland and a low towards the Azores.
See fig 6 at http://www.netweather.tv/index.cgi?a...r;type=winter-
forecast;sess= for the forecast from this year's pattern.

--
Graham P Davis, Bracknell, Berks., UK. E-mail: newsman not newsboy
"I wear the cheese. It does not wear me."

Will

I remember back in the early 1960s (at Bomber Command, my first posting), plotting the 100mb
chart and it being whisked away by N. E. (Neddy) Davies for analysis.
He seemed to spend most of his time working on these charts - never came up with any solid
theory, but was always explaining
the development of the weather using his ideas. He wrote several papers in "Weather" on the use
of 100mb data.

Roy
++++

"Will Hand" wrote in message
...

"Keith(Southend)" wrote in message
...
The question I keep asking myself is what has caused/is causing this
pattern change? We know the jet stream buckling and doing some odd things
to cause the blocking, but what set it off.?

Keith, not really sure but these things are often triggered by events in the
stratosphere.

Many many years ago some 'old lag' forecasters used to swear by the 100 mb
charts for spotting changes over a week ahead in the days before GFS, ECM
etc.

Will
--

"Roy Avis" wrote ...

I remember back in the early 1960s (at Bomber Command, my first
posting), plotting the 100mb
chart and it being whisked away by N. E. (Neddy) Davies for
analysis.
He seemed to spend most of his time working on these charts - never
came up with any solid
theory, but was always explaining
the development of the weather using his ideas. He wrote several
papers in "Weather" on the use
of 100mb data.


.... same thing used to happen at CFO in the '60s. Then/there it was
A.G. Matthewman who used to wander in when we had finished plotting
the 50, 30 & 10 mbar charts - for obvious reasons, not too much data
on those. They were plotted on the 'M' shift after we'd done the 0600
PILOTs and other housekeeping.

I see from my dog-eared copy of the older 'Forecasters' Reference
Book' (blue cover) that at the back there's a whole section about the
stratosphere, and interaction with the troposphere. I regret to say
that it did not figure too highly in my operations! Perhaps it should.

The author of much of that section was Charlie Hawson, and I seem to
remember him hanging about looking occasionally at these charts.

The *specific* interest at BC as regards the 100 mbar charts was to do
with support for the 'V'-force IIRC.

Martin.

--
Martin Rowley
West Moors, East Dorset (UK): 17m (56ft) amsl
Lat: 50.82N Long: 01.88W
NGR: SU 082 023

On Dec 9, 10:53*pm, "Will Hand" wrote:
"Keith(Southend)" wrote in message

...

The question I keep asking myself is what has caused/is causing this
pattern change? We know the jet stream buckling and doing some odd things
to cause the blocking, but what set it off.?

Keith, not really sure but these things are often triggered by events in the
stratosphere.

Many many years ago some 'old lag' forecasters used to swear by the 100 mb
charts for spotting changes over a week ahead in the days before GFS, ECM
etc.

Will
--

Oh no! Not the good old SSW events, a staple of the writings of
Internet winter forecasters! (Together with a whole plethora of
anything that might possibly, on a good day, with a following and
rather cool breeze, induce a temperature drop!). Outcomes Will. If
these things are "*often* triggered by events in the stratosphere" why
are they not forecastable with accuracy on a more regular basis?

Research shows tentative links, but that's all they are. Maybe future
research will bring stratosheric warming more into mainstream
forecasting of the onset of colder conditions in a UK winter. I
wouldn't rule it out, but neither would I go anything like as far as
"often"!

My answer to Keith's question is; "Sorry, but as yet, we just don't
know".

On 10 Dec, 12:09, Dawlish wrote:

Oh no! Not the good old SSW events, a staple of the writings of
Internet winter forecasters! (Together with a whole plethora of
anything that might possibly, on a good day, with a following and
rather cool breeze, induce a temperature drop!). Outcomes Will.

Are you saying then that the stratosphere is not in any way linked to
the troposphere?

I don't research this topic but it would be churlish to think that a
change in the stratospheric circulation might not have an impact
downstream and below. The screaming mid-Atlantic jetstream
(responsible for the remarkable windstorm Klaus) was brought to a
screaming halt in early Feb of this year, and lo-and-behold, there was
an enormous warming event prior to this, which was a real eye-opener.

Richard