Really interested in the progress of Nino, and also in the swift changing of the QBO at present. The wider spread of ENSO forecasts is indicative of greater uncertainty for sure: not convinced personally that the average line has much significance in this context. An average of widening possible solutions is an attempt to simplify a process that is trending to the more complex...and while I am no statistician this feels like an average to be taken with a pinch of salt.
Current SOI may well be interfering with the progress of the warming but I think this will be temporary: currently declining frictionals and consequent reduction in MT will amplify the sense of a more Nina-esque response from the atmosphere, but I cant help but feel this is just a cyclical blip in the passage towards the weak Nino that has been on the cards for many months. Like Tamara I am also noticing the swift increase of winds at 10hpa 60-90N and the likely descending passage of strong vortex winds that will be impacting below 30hpa before long.
But just how strong will trop led feedbacks be in impacting on strat/trop coupling? I was struck last winter season by the ongoing disconnect between trop and strat through the first half of winter, and as a snow lover kept hoping that pacific induced increases in GLAAM would drive a wedge into the decoupled trop vortex and cause it significant grief. It failed twice - and then in spectacular fashion a surge in momentum drove a spike through the vortex that was impressively severe in February. March saw some weather patterns over Europe that were certainly cold - but perhaps more impressive for the extremity of the pattern reversal.
It's my first post on here - and I'll come clean quickly that my last science lesson occurred when I was 15....and that was a while ago now! The basic knowledge I have acquired is most certainly of the basic variety and growing much more slowly than I would wish. I am instead an analyst of history: of patterns, behaviours, cause and consequence. My reading of the last 12 years or so is that we are seeing an ever growing impact of reduced polar ice...of the effect of greater energy release through the autumn and of significant stress between the tropospheric climate in northern latitudes and stratospheric CO2 induced cooling and consequent increase in upper vortex strength. In predicting weather from this I find myself (not for the first time) dancing to Tamara's tune and agreeing that any events created out of a clash between that strong upper vortex and pacific/trop induced forcing are likely to become more severe and harder for models to predict. David is right - analogues pre 2007 (and maybe later) are becoming null and void because they do not begin from the same north pole starting point.
So - to drag this back. Nino probably to continue despite short term cyclical blip, and a winter of atmospheric contrasts set to create a very uncertain future. If an eQBO setup can hold on into December below 30hpa then chances for December blocking increase - but the QBO seems intent on recovering a westerly status as fast as it can based on recent numbers, so we may see the troposphere respond to upper forcing more swiftly. And if that is the case then I see some stormy periods ahead - a winter of ebb and flow, and stark temperature and precipitation contrasts through the season would be my call. Perhaps not a bad thing - it would offer something for everyone...of any weather persuasion.
Whatever happens - happy winter greetings to all....here's to a lot more learning and some properly interesting weather events in the NH.