You provide a fantastic educational resource, do not change a thing. I am just an old codger who has read hundreds of these over the years.
As far as 2015 and NAO goes I have my biggest issue with people who use monthly indicators to say oh we scored big and the NAO was positive for the month of Feb, when in fact if you delve into dailies you see a transient block on the days of the biggest storms . Recent examples are Feb 13 Feb 15 and March last year. Heres the rub, it is nearly impossible to forecast months in advance transient blocks. They can pop up out of the blue or disappear overnight. The biggest wildcard in the deck. All it takes is a 2 day ridge to turn a mundane 6 to 10 storm into a 18 to 24. If you loop the Atlantic this season you can see these blocks pop up in the Middle of the ocean slowing the monster sub 960 storms out there. Deep storms can pop ridges slowing themselves down too. Just my opinion