Looking at the 700mb anomaly charts, I can see a mixed October acting as a transition month after which mid-lat blocking starts to build to higher latitudes in November. By December we have proper high-latitude blocking but not without interruptions. Seeing the largest area of +ve anomalies near to Svalbard and extending towards Siberia is promising for some long-fetch continental cold.
The blocking becomes very dominant in January - CFS has been showing a similar idea for some time now, and it does resemble what it got up to prior to March 2013....!
In February the blocking starts to wane but the anomalies still look loaded with potential considering the over-energetic nature of the CFS model, which tends to generate strong storms that force their way to higher latitudes that it is realistic to anticipate.
In fact, if you take the fact that CFS hasn't wavered much on the broad theme of the winter months over the past few weeks, and then adjust the -ve anomalies in the charts southward a bit to account for that poleward bias... well, then you're looking at a potentially very cold winter being suggested.
It's just one model though, and there are numerous others out there - which Gavin P reviews in his excellent seasonal outlook videos.
Firstly, there's the Met Office's ensemble model, which I have some respect for, and has offered support on previous updates - so my eyes are on that one when the new charts come through.
Next is JAMSTEC/JAM. Not sure I really take much stock in that one as it's a bit hit and miss, but it would be nice to get that one in support.
Then there's the BCC - now that model is a bit of a joke IMO, as it's been way wide of the mark for the last few seasons.
There's a couple of others but I can't recall them off the top of my head and even if I could I don't think I'd have much of a clue regarding their pros and cons.
Originally Posted by: roger63