Sorry, but 10 years of following the models tells me that this is standard sine-wave fare. Azores high attempting to ridge into GL with a glancing northerly to follow as troughs disrupt over GL. As Retron says, no sign of anything interesting for long term cold. Yet.

Yes, but what about the heights over the arctic and the WAA over alaska? Without those I would agree, but that high has only two places it can reasonably go, over canada or to greenland. And the later option is northern blocking; I'm not saying a cold spell is imminent by any means. But with such high heights being forecast, the PV looks like its going to split. I would say that a cold spell in the first week of December looks likely, or at least as likely as it can be at this range. 

http://www.meteociel.fr/modeles/gfse_cartes.php?ech=204&code=0&mode=1

-14 850s into Shetland.  Looks like a short sharp shock

Yes but presumably you are talking about 850hpa parameters for the UK. The broader picture of an arctic high forming and making its way towards greenland has been consistant across all models and the ensembles for the last 2 or 3 days. And while surface patterns deviate quite alot, the upper patterns do much less. All I am saying is, there is strong evidence (in my eyes) of northern blocking developing in the arctic because of this. I understand there is no agreement as to how this will affect the UK, and especially when it will. But the way I see it, unless that high gets pushed into canada we will see a cold spell caused by greenland blocking which could happen anytime in the last few days of november or the first week in december. 

I'm really struggling to see where the flaw in this is. A low AO tends to split the PV and will often bring a cold spell to the UK. Sure the lag is uncertain, as is the exact method it will happen. But I don't think a stubborn mid atlantic high is really going to be an issue against a greenland block and the PV moving into scandi. 

http://cdn.nwstatic.co.uk/gfsimages/gfs.20131122/18/186/npsh500.png

18Z is an upgrade, notice the warmer colours between alaska and russia. 

Quantum
I would dearly love your projections to be realised just for the amount of effort you put into it
As it stands I have to agree with Ben and can't see too much other than a lift and sink scenario that keeps reloading west to east.

it might not be that easy for it to sink thou Neil little pieces off energy run along the southern flank of the high if you look also depends on energy in canada as James earlier

http://www.meteo.psu.edu/~fxg1/ECMWF_0z/hgtcomp.html

if u run it here you can see it better with gm small amounts of energy  left and right that would be hard to sink imo

http://www.meteociel.fr/modeles/geme_cartes.php?&ech=210&mode=0&carte=1

Thus the scadi trough comes more into play as long as Canada plays ball.

Advantage of a projector.

My glass is not full either  more runs required as always but intresting sfuff

http://www.meteociel.fr/modeles/geme_cartes.php?&ech=240&mode=0&carte=0

GEM deep in FI.  GEM likes this pattern, but it stays inthe relams of Fantasy.

Meanwhile in the reliable and semi reliable we find these:

http://www.meteociel.fr/modeles/geme_cartes.php?&ech=120&mode=0&carte=0

http://www.meteociel.fr/modeles/geme_cartes.php?&ech=144&mode=0&carte=0

At least it will stop raining IMBY!: http://www.meteociel.fr/modeles/ukmo2.php?nh=0&ech=120&carte=1021 UKMO

http://www.meteociel.fr/modeles/ecmwf.php?ech=240&mode=1&map=0&archive=0  ECM deep  Fi

and the reliable:  http://www.meteociel.fr/modeles/ecmwf.php?ech=96&mode=1&map=0&archive=0

So, the models say largely dry and mildish for the forseeable.  A seasonal end to Autumn seems probable.

Good morning. Here is the report on the midnight outputs from GFS, UKMO, GEM, NAVGEM and ECM for today Saturday November 23rd 2013.

All models show High pressure the dominating factor to our weather centred down to the West or SW. As a result dry weather will ensue for most areas with the exception of isolated showers near coastal areas. Frost and fog patches will be commonplace over the coming days but will be tempered in amounts for a period towards the middle and end of next week as winds back more towards the NW and strengthen somewhat carrying cloud and some rain towards the north and East midweek, clearing again by the weekend with a return to similar synoptics as we have now with High pressure well in control likely to be centred over or close to Southern Britain.

GFS shows very little change through it's latter stages this morning. As our High declines SE'wards later then a new one takes control near to the SW separated by a spell of rain on a cold front. This means that frost would then return late in the run as the weather settles down once more for most away from the far North.

UKMO closes it's run this morning with High pressure close to the SE and to the West with a weakening trough dissecting the two. So some cloud and a little rain looks like moving East or SE late next week to be followed by a return to High pressure based weather with frost and fog patches.

GEM shows a much more aggressive NW flow developing later next week with gales and rain at times in the north and East while the South and West hold on to largely dry and breezy conditions with plenty of cloud hence little in the way of frost and fog later.

NAVGEM also highlights a strong NW flow late next week and the weekend with rain reaching Northern areas with the South staying dry, breezy and rather cloudy with average temperatures.

ECM too shows a short spell of NW winds when the North and East in particular might see some rain but this becomes quickly replaced by High pressure building across the UK from the Atlantic with a return to fine and dry conditions with frost and fog patches night and morning.

The GFS Ensembles continue to show largely normal conditions for this time of the year with temperatures never straying far from either side of average. However, with High pressure around especially in the South frost and fog is possible at times as well as some rain later as Low pressure to the North allows front to cross the North in particular in the second half of the run,

The Jet Stream remains to the North of the UK and shows that the main core of the flow remains there for the foreseeable future with the direction turning SE over Europe as it sinks down on the far Eastern flank of High pressure near to the UK or in the Atlantic.

In Summary very little has changed today with a High pressure dominated pattern persisting. There are short intervals when weakening troughs could cross down over the Uk from the NW with a little rain but the pattern is always favoured to reset once passed to maintain the anticyclonic theme with any meaningful rainfall held well to the North and NE. Frost and fog will continue to be a feature especially early and late in the period with a milder interlude midweek lessening this risk for a time as increasing winds and cloud in association with one such trough crosses SE later next week.

I'd agree with that - a run-of-the-mill spell looks pretty much certain now, which will probably last into the first week of December at least. The GEFS is showing an increasing "sine wave" pattern, indicative of more mobility than of late and EPS shows a good deal of spaghetti too, also suggesting a lack of blocking in the output.

With no polar upper high in prospect the only hope for coldies in the medium term is of the odd transitory shot of cold as ridges topple eastwards.

EDIT: Here's the 0z ECM ensemble for Reading. It shows the transition to near-normal conditions well:

http://oi44.tinypic.com/24obwnt.jpg

Damit, the thing I have dreaded seems to have happened this morning. The bearing high is moving towards canada  instead of greenland. Still, there is plenty of chance for it to get back on track, and the ECM is nearly there. 

  On all counts.

Shades of the end of November 1988 in today's charts?

It's a long road that we're on, and I still don't believe that we'll establish any persistent blocking until late next month, although 10 days leeway has to be allowed for due to the outrageous uncertainty that comes with such long range anticipations.

At the moment we're seeing the models project some amplification and then knock it down a bit, repeatedly, and this is typical of when there are signs of change emerging - remember back in late June when the models were trying to start the prolonged fine spell about a week or so too soon? ...and that was a less complex situation than we have know.

This is what creates the infamous 'model rollercoaster' that we see every winter, as a signal for one spell of blocking can lead to 3-5 predicted spells that never materialise 

Thank you Martin for your output. ..No rain will be a change..