"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
--