I think that we touched on this a couple of days ago - and I'm not sure that there's a simple answer.  Essentially, leaving aside the matter of sudden stratospheric warming, to get upper highs to the north you need warm air advection (WAA).   The problem is that  you cannot get WAA to higher latitudes through the path of the jetstream.   So, the jet needs to buckle - but I'm not sure many understand whether the buckling jet promotes WAA or whether a surge of warm uppers is what disturbs the jet.

Obviously a upper high is what is needed to create a block and a surface high without support above tends to be more transient and more likely to move eastwards with the prevailing flow.

The biggest factor in the lack of cold in the outlook is still the close proximity of the mid latitude high in our vicinity and the dominance of the high pressure belt to our south.  Unless that recedes south and/or weakens then the jet can only ride over the top.

I am reassured that the models don't get the detail right beyond days 4-5.  The last cold spell faded away at close range and the current high pressure dominance now looks less secure, with a LP system diving SE at Day 5 which wasn't really showing up a few days ago.  But either way, it's still only a transitory cold blip behind a cold front and nothing longer lasting.

http://www.theweatheroutlook.com/charts/gefs/gefsens850London0.png

Still a spread from December 1st

All models currently show High pressure across NW Britain with light and slack winds across the UK. Trapped under this High pressure as expected large amounts of cloud has formed and spread out to give many areas rather cloudy weather which looks like lasting through much of this working week. However, as always some breaks will appear in the cloud and allow frost and fog to form overnight which will continue to occur over the coming nights too. Through the middle of the week Northern areas will become milder for a time before a cold front moving SE at the end of the week starts the weekend off with a chilly NW wind and some bright spells and the odd shower following a band of rain SE on the front through Friday.

GFS then shows High pressure reasserting it's influence across Southern Britain at least for a time early next week with bright and dry conditions while the North quickly become more changeable again with Westerly winds and some rain. This changeable theme then spreads further South and East later next week with a marked wind increase by the second weekend as an unusually deep depression lies to the North, giving severe gales, heavy rain followed by wintry showers to all areas to close the run.

UKMO shows a cold and breezy start to next weekend with wintry showers possible in the East and frost at night. Conditions then moderate through Sunday as a ridge builds from our Atlantic High while the North sees milder Westerly winds returning on Sunday.

GEM today also shows a NW flow to start the weekend, rather cold with some showers for a time, wintry on hills. As we move into next week it's trend is for more unsettled weather to extend to all areas by the middle of the week with wind and rain for all as the High finally collapses and dissolves to the SW.

NAVGEM keeps High pressure across the South to start next week with a milder Atlantic Westerly flow developing across the North. The South would likely see frost and fog patches night and morning while the North is less cold and rather cloudy but mostly dry.

ECM also shows High pressure across the South to start next week although it pulls slowly South and weakens as more instability in the atmosphere pushes down from the North by midweek with the threat of rain increasing for all, first in the North. Temperatures would be close to average through the period.

The GFS Ensembles show a slightly colder domination this morning as the benign conditions of this week slowly give way to more unsettled weather with rain at times and temperatures likely to be close to or rather below normal later in the run which would allow for some snowfall to occur on Northern hills at times.

The Jet Stream driving the weather at the moment is well to the North of the UK and remains there for some time to come. There is signs then of a tilt in the flow to run it SE across the UK at least for a time as pressure falls to the North next week.

In Summary the weather this week will see only slow changes and variations day to day. Anticyclonic gloom will be prevalent but some clearer slots could give rise to frost and freezing fog patches at times before midweek. Then later it looks like most models support an injection of colder clearer air from the NW at the weekend. In Week 2 the trend seems to be for things to slowly turn more unsettled and windy with rain at times as our High finally becomes slowly eroded from the North. Though no prospect of marked cold is shown again this morning some change of air mass to Polar maritime later could bring some wintriness to showers over higher ground especially in the North.

Another perfunct summary, Martin.

The current stable conditions courtesy of the UK Slug will continue a while, with as you say a short change of airmass over the weekend to clear some of the gunk away.
Nothing remotely 'wintry' looks on the table for some time, but keep watching for changes as they do sometimes occur at short notice.

Not really anything constructive to add to the above - thanks as always Gibby. This kind of set up wil resolve at some point - patience will be needed among those who seek cold, but in my favourite corruption - 'at least it won't be MILD'... (or at least not excessively so!)

As if to relieve the monotony GFS 06Z generates a monster low in FI LOL.

Best come back a week on Thursday for a change in output. Will be winter then.

GEM the only interesting output I can find today!. Oh dear, hopefully these are the dark days before the dawn of the next Daily Express "nuclear winter"

Wasn't there other output in the last 24-48 hours that has done the same thing?  There was one run, I think GFS, which pulled the PV down into southern Scandinavia and gave a brief potent northerly flow over the British Isles.

The pattern remains extremely mobile and there's no sign of any blocking at all, anywhere around the entre northern hemisphere. Even the upper heights that develop over Alaska get pushed away quite rapidly.

I'm sure we have all seen these patterns before and equally we know it can change quite quickly.

Hang on a minute, bit of a dip showing in the GFS 06z ensembles after 4th December with only a handful of members not at least buying into something a little colder, something that was hinted at in discussion on this thread yesterday!

http://modeles.meteociel.fr/modeles/gens/graphe_ens3.php?x=314&ext=1&y=138&run=6&runpara=0

Hi all,

Here's today's video update:

Thniking About January;

http://www.gavsweathervids.com

Also some shorter range stuff in there, but not much going on - GFS seems quite keen on some sort of storm around Dec 6th-8th though, which could provide a bit of interest.

Is it really that bad already Gav?