and even when you look at the total number of storms, NYC is higher than the other two cities with a +AO, and I think the total number matters more than the percentage.
ah okay I thought it was the -PNA not the +AO, this is why we have to be so careful with stats. Logic must also be applied; I like how you restated with the converse statement of NYC more likely to see a 4" snowfall when the AO isn't +
Mine too, the first time I actually experienced thundersnow and the amazing snowfall rates that go along with it. It's why I love day time snowstorms so much.
I wonder how slowing down of ocean currents, like the gulf stream, will impact it?
Maybe ocean currents are slowing in one area and speeding up in another to balance it out?