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http://meteocentre.com/analyses/map.php?lang=en&map=eur_full&area=eur&size=large Things seem to happen by stealth with an easterly feed as eyes are normally fixed on the atlantic. However at 11Z there is an upper high over Scandinavia of 564 DM. Colder air is flooding out of Russia and across Poland. The easterly feed is modelled to last a few days so it is to be expected that northern Europe will cool down somewhat this week and perhaps provide a source of cold that could with time affect the UK.

Perhaps noteworthy that a closed circulation is predicted on both EC and GFS 500 mb heights charts close to N Scandivavia. This appears to be the only warm closed circulation at high latitudes in the northern hemisphere and if correct and if maintained could be the start of a decent block.

With an upper cold pool sitting close to the south, 850 mb temperatures around 2 C and surface temps of 8 - 9 C we are currently in a colder interlude before models predict a surge of tropical continental air to move north from north Africa over the next few days. The warm ridge to the east which has been such a persistent feature over recent weeks giving the UK a warm autumn looks likely to persist and there are hints that this warm ridge may result in a dominant Russian high taking hold. A resurgent Atlantic will at times inevitably erode the block to the east as shown by this mornings output but at times when the Atlantic flow weakens the Russian high may well extend westwards producing drier, chillier spells.

There has been a trend over the last few days to backtrack in favour of the block.

I have not been keeping an eye on the distance between the long waves but I seem to remember reading that if the distance between the troughs or ridges in greater than around 4000 miles then the waves can start to move backwards. Perhaps this is happening and the models are now catching up ?.

Yes this will eventually likely happen as it normally does but for the next week or so high pressure over Europe and Scandinavis looks more likely to be influential.

Generally the trend over the last few days has been for the models to strengthen the block to the NE in the timeframe T+96 to T+144. Beyond 144 models have generally eroded the block, some quite dramatically but each day the back track has continued and it is now looking likely that we will end up with an anticyclonic spell. Warm air aloft being sucked up from the SE could lead to a low level inversion with chilly misty conditions at the surface in an east or southeasterly drift from cooling continent.

12Z UKMO has stronger block to NE at T+96 than 24 hrs ago.

00Z ECMWF now showing an easterly component Sunday through to Thursday next week. This has extended an extra day since the previous run.

High pressure sitting across the UK in November can often result in colder conditions and is perhaps more likely than deep cold reaching us from the NE..

A much more plausible looking senario from ECMWF this evening past T+144 with an eventual NE drift and chilly conditions which could possibly last several days.

http://mp1.met.psu.edu/~fxg1/ECMWF_0z/hgtcomp.html%C2'> At any given height level, 500mb in this case, it is where a cut off low or high forms in the normally smooth running contour lines around the hemisphere. It can sometimes indicate a weaker circulation in all or part of the hemisphere and may be more prone to blocking.

ECMWF 6-10 day 500 MB chart is showing a closed circulation to the north of Scotland which is pretty rare and would help to cement the block. Whether it is still there in a day or two remains to be seen but this is significant.

Latest T+72 Fax holds UK occlusion and Atlantic low several hundred miles further west compared to previous run. A significant shift.

Dewpoints over Russia this morning are more typical of mid winter than late October. http://www.wetterzentrale.de/pics/Reurmetd.html

If the current and rather persistent stratospheric warming leads to increased blocking it will be interesting to see if this results in anything unusual during April. Northern blocking in the Spring is quite common but a month without some extreme occurring is becoming less common.

There does seem to have been a subtle trend to a quieter colder spell around this timeframe which has been a recurring feature over the last few days. Are we gradually entering into a change of type 'beneath the radar'. Is the recent short but significant strat warming playing its hand.

Look at all the cold to the east...what a waste..sure they don't appreciated it over there. http://meteocentre.com/analyses/map.php?map=eur_full&date=2014013109&size=large〈=en&area=eur

-49 deg C top right at 09Z this morning. http://meteocentre.com/analyses/map.php?map=eur_full&date=2014012909&size=large〈=en&area=eur

A bit like this then; http://meteocentre.com/analyses/map.php?lang=en&map=eur_full&area=eur&size=large

Slight retrogression of the pattern as the Arctic high slips south and replaces the declined Scandinavian high and trough to the NE digs south over NW Russia where temperatures yesterday were -44 deg C. The low to the NW of the UK looks like it is about to start edging SSE. All in line with near time model predictions. http://meteocentre.com/analyses/map.php?lang=en&map=eur_full&area=eur&size=large

Events do seem to be unusual again this year with weeks and weeks of exceptional storminess and now an apparently immovable trough over the UK and a block of high pressure sitting over Northern Scandianvia of no great intensity but of unusual persistence when compared to the last 25 years or so. The presence of this pattern has caused the cold over Scandinavia and NW Russia to intensify and expand in all directions e.g -15C in Poland this morning. So far the UK has remained on the edge of the cold but as the cold intensifies over Europe there must be at least a worry that this intense cold will very gradually expand further and further west eventually engulfing the UK.

As some of the output has been indicating over the last few days....lower dewpoints creeping ever closer from the east. http://www.wetterzentrale.de/pics/Reurmetd.html

The 12Z GFS charts for T+6 and T+384 are almost the same...remarkable !.

Pressure rising slightly over and to the NE of UK with biggest falls over the western Med as the low slips SSE as modelled. This should cause some backing of the flow over the continent. http://meteocentre.com/analyses/map.php?lang=en&map=eur_full&area=eur&size=large