On 05/03/10 16:45, Dawlish wrote:
On Mar 5, 4:14 pm, Graham P Davis wrote:
On 05/03/10 15:16, Will Hand wrote:







"Graham P Davis" wrote in message
...
On 05/03/10 12:48, Will Hand wrote:
Didn't Will say that it would change as we approach the Spring
Equinox, with the Sun moving North of the Equator it would start to
drag the Jet Stream away from its Winter holiday in Morocco?

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I did Bonos, a long time ago now as well!
I stand by it still.

And I'll stick to the SST anomalies keeping it down south for the most
part. Mind you, the anomalies are said to have less effect during the
summer so that may be some small crumb of comfort.

Graham, can you explain why such a relatively small patch of cold water
(40N 40W) on the global scale can affect the whole NH dynamics at 9Km
and above? Might it not be that the NH SST anomalies are symptomatic
rather than causal?

I think I've already answered this in an earlier response to one of your
queries on this subject. Also, it's hardly a small patch of water.
Perhaps you'd be better off going to the horse's mouth and checking on
the work by Lamb and Ratcliffe back in the 60s and 70s.

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

- Show quoted text -

I'm sure that there is something that can explain the end of this
winter cold (when it comes, for all areas and notwithstanding the fact
that spring has definitely arrived on the south coast of Devon, for
now, at least!) but I'm not at all sure either of you are correct in
your different reasons - though both probably have some part to play.
If one of you was correct in this, or if Lamb and Ratcliffe were
correct, the MetO would have a far better record in seasonal
forecasting than it has.

That assumes they still use it. My impression was that (a) it had been
forgotten about and (b) it was old science that hadn't been proved
recently (but hadn't been disproved either) and therefore not worth
bothering about.

Forecasting that it is highly likely to get
warmer as winter turns into spring seems a bit self evident Will.
Also, that really is a relatively small patch of the North Atlantic
Graham to be affecting our weather so greatly for 3 months. Could it
really have prevented cyclogenesis and a westerly flow across to us?

Small? It extends right across the Atlantic! Based on the first signs of
a cooling in the region, I did warn back in November that we might see
an easterly winter. Also, the seasonal forecast from Netweather included
a forecast pressure chart based on the SST anomalies. I reckon this was
a pretty good forecast of the pattern and, for good measure, forecast
the jet stream would be displaced southwards.


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