Polar vortex will be taking some hits in next few weeks as we see our first big stratospheric intrusion take place. Heart of said intrusion looks to occur in the upper stratosphere, with effects extending down to the 20-30mb region.
+QBO and suddenly record-low 100mb eddy flux values don't support a long-term polar vortex break-down, and while long range GFS is optimistic in terms of really hammering the vortex, we all know the caveats that come with such long range models, especially in the stratosphere where we don't have the luxury of certain sampling data, i.e. airplane OBS and surface station OBS.
That said, expect an attack on the vortex to commence in a good week's time, reaching its peak in the 10-15 days down the road. I anticipate a reorganization of the vortex in due time following said peak, with the aforementioned +QBO/record low 100mb flux.
Wouldn't be surprised to see the vortex have significantly more issues dealing with another intrusion of this magnitude a month or so down the road.