Interesting article.
Funnily enough I was reading about the North Atlantic Oscillation a few days ago and I was thinking that we might have been in the negative phase this winter as the weather (much colder and drier than normal) was similar to the negative phase. I wonder if we're moving to the positive phase of the NAO now.
Our forecast is wet and windy which is more indicative of the positive phase and it's been mild recently. Not sure what the story is for the US though. I don't think Europe could be in the +phase whilst the US is in the -phase.