+SOI has been strengthening, too.
It didn't break +5 all year, despite cold subsurface, but has recently gone through that mark for the first time since March 2023. It's a late-blooming La Nina, by surface parameters.
ENSO subsurface has been cooling rapidly. Latest has us getting close to -6c, which is well within "Moderate La Nina" range.
I've found a significant correlation between this and the North Pacific pattern - particularly the PNA pattern. Negative anomalies favor -PNA conditions in the Wintertime, so I would watch for that pattern to develop as time moves on.. when this recent +PNA began, the subsurface was Neutral. It's really cooled in the last few weeks.