I see where you are getting stuck, you are taking analogs too literal. There are only really 2. The mechanics of the situation don't change, it only changes the amplitude. If forcing is west-based, that's +PNA and a stronger +PNA if it's >2.0 in the west (RONI). I'll take a really, really strong +PNA. You just don't want it to get too close to the west coast, US, which is more tropically east-based