I think if the longer-wave upper-trough system has strong-enough Jetstream boundaries between them and the sub-tropical ridge, a SSW is more likely to be isolated and not affect the weather layer so much. However, if convergence streams (near the tropopause) are weaker, higher temperature and wind anomalies may leak into the westerly belt. The polar jet I'm referring to.

Strange spike on ozone hole charts at
http://www.cpc.ncep.noaa.gov/products/stratosphere/polar/gif_files/ozone_hole_plot.png
around 19-21 October - difficult not to believe it's an error from instruments or transposition of data? otherwise ozone hole disappeared for what..a day?...then came roaring back to finish at about level for 2016.Seems a bit odd.

Looks as if were about to see the final warming and breakdown of the PV in next few weeks. I think this would be earlier than normal in the ozone hole era.





Zonal winds look set to take a nose dive over the next week also.

Smallest hole since 1988 confirmed!

https://www.nasa.gov/feature/goddard/2017/warm-air-helped-make-2017-ozone-hole-smallest-since-1988

Zonal winds @ all monitored levels in stratosphere @ 60S as of 14/11 are still stronger than at same moment last year.

https://acd-ext.gsfc.nasa.gov/Data_services/met/ann_data.html

By current forecasts, Zonal Wind at 50hPa,(remembering one suggested proxy for final warming being winds declining to 1ms at that level), look to last a bit longer - by last week of Nov though easterlies will be present@10hPa(again the same forecast from nasa).

If the final warming date of last year is known it might be possible to say if the above situation is a little odd - given the +ve anomylous heat flux the stratospheric vortex has been subject to this season, and the much larger ozone hole of 2016.

Currently into easterly phase QBO often associated with increased planetary wave activity in polar region.Always possibility of a weakened vortex and perhaps (hope)significant cold outbreaks later.

April EP flux looks to have been anonymously positive
http://www.cpc.ncep.noaa.gov/products/CDB/Extratropics/figs7.shtml

May data should be released any day.
I thought on June 1st, wave activity seems to have actually penetrated well into the polar vortex, and perhaps again on the 3rd. (Select "Southern Hemisphere" atop the drop down menu then "Zonal Mean Zonal Wind & EP Flux" at bottom of list.)
http://ds.data.jma.go.jp/tcc/tcc/products/clisys/STRAT/