That JMA update is striking in how it brings cold 2m temp anomalies to the UK but not the rest of NW Europe, and does so while delivering above average precipitation.
I can think of only one surface pattern that could achieve that - strong blocking to the NW and low pressure running SW to NE through the UK, engaging with cold air and pulling it in across the UK while tending to keep the rest of NW Europe on the mild side.
On the face of it, that would probably deliver a lot of marginal events and many disappointing cases for the SE in particular - but I reckon there would be far wider variation on the theme than the model suggests, with some cold air masses making it into NW Europe while the UK sees some proper cold for a time.
This is only one model, and the odds of verification are, as always, minute - for the most part I've carried out this interpretation of pure interest.
Having said that, from a clash of the emerging signals for blocking this winter with the recent suggestion from most models of an active Atlantic storm chain affecting the UK under a more westerly regime, something like that JMA outlook seems very justifiable... just my opinion of course.
Originally Posted by: Stormchaser