I've also found that sea-level height, or sea-level height anomalies has a very high correlation with the H5 pattern +time. Can you explain that one Phil?

Y’all need to stop posting CFS trash on here, that s**t might as well be straight out of the Y2K era. There’s a reason that joke of a seasonal model is being decommissioned before decade’s end.

Z500 verification scores demonstrate that you are wrong. The EPS and EPS AIFS have been the highest performing model suites.

Well there is a high correlation. Gravity waves, in this case a Kelvin wave probably propagates to the mid-latitudes forcing a +PNA. You can watch it as it happens in the future, when East of 180W at -150m sees a big negative or positive new anomaly, check out what's happening in the N. Pacific, or which direction it's going.

The +PNA is a result of the WPAC convection that forced the downwelling wave in the first place, not the other way around. Subsurface thermocline shoaling (or the lack thereof) isn’t forcing a +PNA, lol.