I do have a rule that I never trust ensemble guidance for blocking highs, especially ones to our NE. Often their persistence seems to involve minute details that the lower-res ensembles tend to overlook. In theory we can't be far from a time when ensembles are of sufficient resolution but I don't think we're there just yet.
I expect the block will fight on and on, and we'll be waiting for it's impacts on the vortex (aided by ridges from Alaska/Canada at times) to trigger a shift in the position of the blocking features, hoping that they spend at least some time in a place that's good for sending some cold, snowy weather our way. Arguably it's snow-fanatics in the south that could benefit from it most, as that's where there has been the least occurrence over the past few years (only had settling snow here on one occasion since Jan 2013 and some places have had none at all!), plus there's not the concerns over flooding - instead a deficit of precipitation in parts.
I still wonder how many years I'm going to have to wait for a powerful channel low bringing blizzards to the south to take place in my lifetime.
Anyway, the nature of the blocking high in the early part of January looks like a classic 'dangling carrot' to me, one that has a habit of teasing us with a whiff of properly cold air grazing the northeast for example. So it is that rainfall is the major concern - and let's face it, a big block just to our NE causing storm systems to stall out over the UK is among the worst possible paths to be following following recent and current events in some parts of the nation. The only thing worse is a hyperactive jet piling storms in with hardly a pause for breath (2013/14 being the ultimate example), which thankfully isn't looking to be on the cards given the relaxing vortex and opposite tropical rain pattern over Indonesia to what was seen in '13/'14.
I do have a strong 'gut feeling' that we're going to get somewhere by late January wrt cold, snowy conditions across much of the UK at some point or other, and that a retrogression of high pressure from Scandinavia to Greenland will be involved. In light of which I will be taking great interest in how the deep cold moves about in the coming weeks - we don't want to find ourselves with a top drawer pattern but the cold vacated from the source region. Just look at how heavily the cold near/over Siberia is modulated by the high-850 hpa temp airmass being advected up there in the near future (850's may reach +4*C!).
What would be rather typical of an El Nino type winter would be for the optimum setup to be rather transient, with the blocking heading too far west before too long (west-based negative NAO) but there are actually hints that the current El Nino is losing some of it's classic form in favour of a more central type forcing which if true will certainly work in our favour in terms of the likely place for blocking highs to set up shop... this is another feature that I'll be watching with great interest in the next fortnight.
For evidence of that I'm afraid all I have for the mo is this poorly focused snapshot taken from discussions with a good friend of mine:
It reads 'Strongest Forcing to shift from 110W to 145W during late December into early January'.
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T-Max: 30.2°C 9th Sep (...!) | T-Min: -7.1°C 22nd & 23rd Jan | Wettest Day: 25.9mm 2nd Nov | Ice Days: 1 (2nd Dec -1.3°C in freezing fog)
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