"Dawlish" wrote in message
...
On Sunday, December 16, 2012 6:39:36 PM UTC, Teignmouth wrote:


thanks you Will. After reading and learning from these, I doubt you will
be as willing to draw such strong links to SSW's and especially to very
weak ones, ("stratwarm" is a term used nowhere in the article, or the
blog). I could be wrong on that, of course.





In the 1st link that Will provided by the Met Office:



The new model, dubbed the "high top" system, is different from the
previous system as it takes into account something known as sudden
stratospheric warming's (SSWs) - which have previously been shown to be
responsible for cold conditions at ground level.



SSWs happen when the usual westerly winds in the stratosphere, between
10km and 50km up, break down and ultimately reverse.


Errrrrr yes. We all know the atmospheric signatures of strong SSWs. We also
know that the MetO have changed their models and incorporated strong SSWs in
their forecasting. So your point is about the effects of the weak SSW that
Will got hopelessly wrong? Will understands exactly what I mean. A pity you
don't.

==========================

The point is, is that even relatively weak or shortlived warmings will
decrease the zonal wind and if there is an existing block that will help
prolong it. It is no coincidence that the last block retreated eastwards in
the models when the stratwarm ceased.

Will
--

On Sunday, December 16, 2012 7:29:28 PM UTC, wrote:
"Dawlish" wrote in message

...

On Sunday, December 16, 2012 6:39:36 PM UTC, Teignmouth wrote:





thanks you Will. After reading and learning from these, I doubt you will

be as willing to draw such strong links to SSW's and especially to very

weak ones, ("stratwarm" is a term used nowhere in the article, or the

blog). I could be wrong on that, of course.











In the 1st link that Will provided by the Met Office:







The new model, dubbed the "high top" system, is different from the

previous system as it takes into account something known as sudden

stratospheric warming's (SSWs) - which have previously been shown to be

responsible for cold conditions at ground level.







SSWs happen when the usual westerly winds in the stratosphere, between

10km and 50km up, break down and ultimately reverse.





Errrrrr yes. We all know the atmospheric signatures of strong SSWs. We also

know that the MetO have changed their models and incorporated strong SSWs in

their forecasting. So your point is about the effects of the weak SSW that

Will got hopelessly wrong? Will understands exactly what I mean. A pity you

don't.



==========================



The point is, is that even relatively weak or shortlived warmings will

decrease the zonal wind and if there is an existing block that will help

prolong it. It is no coincidence that the last block retreated eastwards in

the models when the stratwarm ceased.



Will

--

Show us the research that shows that a very weak event (the SSW last week was exactly that), which does not actually propagate to the surface (it didn't), produces an enhanced effect to a surface block.

"Dawlish" wrote in message
...
On Sunday, December 16, 2012 7:29:28 PM UTC,
wrote:
"Dawlish" wrote in message

...

On Sunday, December 16, 2012 6:39:36 PM UTC, Teignmouth wrote:





thanks you Will. After reading and learning from these, I doubt you
will

be as willing to draw such strong links to SSW's and especially to
very

weak ones, ("stratwarm" is a term used nowhere in the article, or
the

blog). I could be wrong on that, of course.











In the 1st link that Will provided by the Met Office:







The new model, dubbed the "high top" system, is different from the

previous system as it takes into account something known as sudden

stratospheric warming's (SSWs) - which have previously been shown to be

responsible for cold conditions at ground level.







SSWs happen when the usual westerly winds in the stratosphere, between

10km and 50km up, break down and ultimately reverse.





Errrrrr yes. We all know the atmospheric signatures of strong SSWs. We
also

know that the MetO have changed their models and incorporated strong SSWs
in

their forecasting. So your point is about the effects of the weak SSW
that

Will got hopelessly wrong? Will understands exactly what I mean. A pity
you

don't.



==========================



The point is, is that even relatively weak or shortlived warmings will

decrease the zonal wind and if there is an existing block that will help

prolong it. It is no coincidence that the last block retreated eastwards
in

the models when the stratwarm ceased.



Will

--

Show us the research that shows that a very weak event (the SSW last week
was exactly that), which does not actually propagate to the surface (it
didn't), produces an enhanced effect to a surface block.

It's common sense, a bit of understanding of what blocking is (not actually
an entirely surface feature at all) and an understanding of atmospheric
dynamics is all that's needed to understand that. Reducing the zonal wind
speed will er lead to less mobility and hence de facto an increase in
tendency for the atmosphere to block. Surely you can understand that? If
not, please go back to lurking properly and read some meteorology text
books, there are plenty around.

Will
--

On Sunday, December 16, 2012 11:13:37 PM UTC, wrote:


[...] a bit of understanding of what blocking is (not actually

an entirely surface feature at all)

=======

Exactly. And although the UK, being peripheral, got just a few days of extremely cold weather, such blocking as there has been has produced a lengthy period of below average (and at times far below average) temperatures over Scandinavia and NE Europe, and indeed Germany and Poland (not just cold but snowy).

Woolings et al 2010 links SSWs and tropospheric blocking for one. And researching into the December 2009 cold, Lin Wang and Wen Chen (Geophysical Research Letters) note this: "Another interesting point is that in previous studies, the downward propagation is usually documented for extreme strong stratospheric anomalies such as major warming or strong vortex intensification [e.g., Baldwin and Dunkerton, 2001; Limpasuvan et al., 2005]. However, the
warmings in this case even do not meet the criteria for minor warming defined by World Meteorological Organization. *It suggests that in addition to extreme strong events, some weaker stratospheric anomalies can also propagate downward and influence the troposphere.*"

("Downward Arctic Oscillation signal associated with moderate weak stratospheric polar vortex and the cold December 2009." Lin Wang and Wen Chen, GRL 11 May 2010.)

It is quite in order to suggest *a greater likelihood* of tropospheric blocking even during a weak stratospheric warming event.

Stephen.

On Sunday, December 16, 2012 7:29:28 PM UTC, wrote:
"Dawlish" wrote in message

...

On Sunday, December 16, 2012 6:39:36 PM UTC, Teignmouth wrote:





thanks you Will. After reading and learning from these, I doubt you will

be as willing to draw such strong links to SSW's and especially to very

weak ones, ("stratwarm" is a term used nowhere in the article, or the

blog). I could be wrong on that, of course.











In the 1st link that Will provided by the Met Office:







The new model, dubbed the "high top" system, is different from the

previous system as it takes into account something known as sudden

stratospheric warming's (SSWs) - which have previously been shown to be

responsible for cold conditions at ground level.







SSWs happen when the usual westerly winds in the stratosphere, between

10km and 50km up, break down and ultimately reverse.





Errrrrr yes. We all know the atmospheric signatures of strong SSWs. We also

know that the MetO have changed their models and incorporated strong SSWs in

their forecasting. So your point is about the effects of the weak SSW that

Will got hopelessly wrong? Will understands exactly what I mean. A pity you

don't.



==========================



The point is, is that even relatively weak or shortlived warmings will

decrease the zonal wind and if there is an existing block that will help

prolong it. It is no coincidence that the last block retreated eastwards in

the models when the stratwarm ceased.



Will

--

Is it "no coincidence" Will? Do; "relatively weak or shortlived warmings will

decrease the zonal wind and if there is an existing block that will help

prolong it".

Where are you getting these "facts" from? Surely you must have evidence to back this up?