Good analysis! As I watch another 2 feet of snow fall today in what is now the wettest winter in Flagstaff in 30+ years, a couple things stand out:

 The active MJO clearly has been a bigger influence on West Coast and SW weather this season. In turn, the NAO, PNA and AO combinations--some of which can be reasonably forecast on intraseasonal scales--demonstrate that some of our wettest winters can come in a La Nina year. Also, we still seem to be transitioning out of La Nina, which may also have some impact. Bottom line--relying solely on ENSO indices seems a recipe for busted forecast...