A semi-permanent summertime high-pressure ridge in the vicinity of the New Zealand marine heatwave much of the past 10 years is likely to regenerate during summer 2023-24. Proposed is an added climate diagnostic supporting an anomalous dry and hot summer 2023-24 climate pattern across Australia causing a major drought.

The latest 15-day upper air forecast for the southern hemisphere (by GFS) reveals an amplifying titanic upper-level high pressure ridge developing southwest of South America. Previously, the 2020-23 semi-permanent Amundsen Sea upper trough was “locked-in” the previous 30+ days and responsible in part for a wet pattern for much of Chile, Argentina, and Brazil. The pattern is about to reverse.