I'm not really interested in if it's going to happen, but I am curious how this being eastern like the model suggests is even worse than it being in the middle. The next post in that thread suggests next winter won't show up (again) if we get a nino like this.
But I did some brief googling and couldn't find much of an answer as to what the positioning of el nino means, lots of pop-weather sites that don't really explain things as well as I'd like. I just find results explaining what el nino and la nina are, not the effects, specially of the location and size (though strength is usually covered).
I'm guessing the location affects the jet streams in various ways and prevents the midwest from getting some arctic air and blocking patterns. But that's just an educated guess.