Subsurface on the TAO/Triton maps are dropping again.. approaching -4c in the central region about -150m. It was waning for a while, but now it's back at borderline Weak/Moderate Nina range. The subsurface has been correlating with the PNA strongly since mid February.
Not so sure this Nina is going to be very weak. Some datasets already show the Nina pretty well established. MEI is pretty Ninaish too.
No doubt it is interesting the PDO was so negative during the recent Nino.
The El Nino last Winter matched the El Nino/-PDO blend over N. America just about perfectly. I always think SSTs are secondary, but according to some sources, there are anomalies up to +15F in that PDO region! Put hot bath water in a room, and you'll raise the temperature 0.1-0.2 degrees. It's also a matter of consistency forecasting, since we don't always know everything, and similar global factors occurring are more likely to repeat: they can be reflected in SSTA's. I also think there is a subsurface variable at play, sometimes identified as sea-level height anomalies.