Third: Right now, the cold spell over Northern Europe is not linked to anything out of the ordinary in the ocean dynamics of the Atlantic ocean.
Last time I looked, we were blaming the jet stream, ie the atmosphere.
Exactly, but to keep things short I omitted that part.
"Blaming" is a bit odd wording, though. We can pretty much explain the "WHAT"'s and the "HOW"'s of the weather pattern of the day, week and month. But the "WHY" is a bit more tricky - in particular WHY do we have that particular weather pattern RIGHT NOW (and why not, in say, December 2004?) All those components (jet stream, storm paths, individual storms, polar front) are linked together in a highly dynamical system. Playing the "blame game" with those components doesn't seem very helpful to me. On the other hand, I will give credit to anyone trying to convey the complexity of the system and how it behaves:
"The jet stream does this and we see that result on the surface".