The problem when someone argues that AGW is causing winters to be warmer or AGW is causing the Polar Vortex to weaken more often than usual. Yes AGW is happening but how it's really effecting weather patterns we still don't seem to have a good grasp on that yet.
Oh but we do need the -EPO to get the cold really loading. The positive PNA is only going to give low level cold not the deep stuff that a -EPO provides.
The biggest problem I have with this new pattern is there is no cold arctic air in Canada. You want Canada like a freezer, having a positive PNA is nice but it only temporary delivers cold down to the Eastern US.
That is a good thing would give us a -EPO. We need that -EPO for a cold load to drop into Canada. Your positive surely helps you guys out in the eastern US with some cold and would help me some too here with big storm chances but need the -EPO too. I don't see how a -EPO would lead to a return of La Nina?. I heard it's getting weaker anyways heading into a moderate one.