[Stratosphere and Polar Vortex Watch]

This is actually a Stratosphere warming where the N Hemisphere stratosphere at 10mb is going to average negative anomaly. 

[Stratosphere and Polar Vortex Watch]

I understand what you are saying with winds. But research is showing something like 21/24 correlation with 10mb warming in December and January negative NAO. Many of the analogs didn't have 10mb air temperature correlation or zonal wind event, and yet became -NAO on +20-35 day lag. Models are crazy with 10mb warming through December right now (it's already happening).

[Stratosphere and Polar Vortex Watch]

10mb is super Stratosphere warming right now. This looks to continue through the last week of December. 

This only ever goes as high as +1200-1800. 

 

500mb of January-February's following 19 years that had Stratosphere warming during this time:
 

Only La Nina (7).

[Stratosphere and Polar Vortex Watch]