On Friday, 3 January 2014 17:24:55 UTC, John Hall wrote:
In article ,

John Hall writes:

In article 20140103111029.77cd8e04@home-1,

Graham P Davis writes:

On Fri, 3 Jan 2014 02:01:17 -0800 (PST)

exmetman wrote:



Hi



The latest midnight run of the GFS model shows the first signs at

T+312 (16 January) of a change in type from the current seemingly

unending cyclonic SWl'y to a more of a blocked E'ly with high

pressure building to the NE of Iceland and low pressure belt being

pushed further south into central France. Colder air will obviously

follow if this scenario pans out...







Again? Will it be 2nd time lucky for an easterly forecast from GFS this

winter?



Since Christmas Eve, Matt Hugo has been pointing out that ECMWF was

hinting at a splitting of the stratospheric vortex - not an SSW - and

that this might produce a change of type.







I don't normally put much faith out as far as T+312 - or indeed in the

06Z and 18Z GFS runs, which I understand don't have such a full data set

as the 00Z and 12Z - but for once the 06Z is consistent with the 00Z in

what it's showing. As early as T+192 the zonal train is shown as slowing

down. However beyond T+240 the operational run is very much towards the

cold end of the ensemble.

snip



The operational 12Z GFS run has reverted to keeping things zonal, which

doesn't come as a great surprise.

--

John Hall "He crams with cans of poisoned meat

The subjects of the King,

And when they die by thousands G.K.Chesterton:

Why, he laughs like anything." from "Song Against Grocers"

ecm 12z, shows a Scandi High...

Keith (Southend)
http://www.southendweather.net
"Weather Home & Abroad"
twitter: @LawnscienceEssx