I was a bit bored at work today so I was reading up on the causes of
the US Snowstorm, but more importantly what causes these Nor'easters.

Now I now the link below is to Wikipedia, and should be taken with a
pinch of salt, but I found it quite an interesting read, in particular
the bit about it being associated with switches from positive to
negative Arctic Oscillation phases, and with the current storm looking
to stall Mid-Atlantic, is it about to help with the creation of a
Sudden Stratospheric Warming event by pumping warm air Northwards over
the UK & Norway, and deep cold air moving South just east of the Urals
into Western Asia in about 7 days time. http://www.wetterzentrale.de/pics/Rtavn1561.png

Full article link http://en.wikipedia.org/wiki/Nor%27easters