FishOutofWater,
The thing is, i disagree on the stratosphere point, because the data support that the troposhere alone leads to AO-negative regime and its because of the less sea ice and the energy in the arctic ocean. This could, of course lead to an weaking of the stratosphere polar vortex, which has not happend jet. Look here: http://www.cpc.ncep.noaa.gov/products/stratosphere/strat-trop/gif_files/time_pres_TEMP_ANOM_OND_NH_2016.png stratosphere in arctic has up to now cooler then the mean
If we get a stratosphere signal which be strong enough to propagate, we will see it like a major warming not just as minor warmings
I'm conditionally in RW's camp here. As FooW points out, we have huge, in-region active heat and moisture sources *now*, in the form of the warm Atlantic water intruding into the Barents and elsewhere on the Atlantic side. This drastically reduces, perhaps even eliminates the the need for imported heat from lower latitudes required to disrupt Arctic weather.
RW is illustrating that we are seeing what in the past would be the expected outcome of an SSW - high-latitude storms, cold displacement, excess heat and moisture north of 65 degrees - but not the corresponding changes in stratospheric circulation.
*When* we have an SSW, which quite likely will happen later this season, we'll get both the effect of the in-region heat, and *more* heat than is currently being imported as a side effect of that event.
The underlying key point I think we need to keep in mind, and which is critical in supporting the events we see unfolding, is the net increases in system enthalpy that have taken place. There is a huge amount of additional heat, actively seeking colder places to go, and not finding them; at least not fast enough that regional temperatures can approach anything like our average baseline.
The prompt problem right now isn't GHG forcing or heat exchange, its the sheer volume of heat in the atmosphere and ocean. It's the thermal equivalent of flood water which has swamped the region. There is just too much of it for the drainage to handle. It has just stacked up waiting its turn to move elsewhere, in some places creating the ludicrous situation of forcing the "drainage" to flow backwards - 250K of sea ice melt/compaction in mid November.
The pot - our climate - is now metaphorically coming to a boil. I suspect signals which we previously were able to use to make fairly skillful short to mid-term predictions are going to become increasingly unreliable as more chaos enters the system. Long term, predictions of things like state change in climate (e.g. ice free arctic) have now become much more solid.