In South America, a drier than normal projection is indicated with average confidence stretching from Peru to Bolivia to Northeast Argentina and Southeast Brazil. A wet regime is likely across northern continent to Northeast Brazil. Anomalous heat builds across northern continent to Central Brazil and across North Chile. The outlooks are based on an analog whereas La Nina and negative Indian Ocean dipole (-IOD) are present during spring coupled with large marine heat waves east of Argentina and east of Australia and New Zealand.

The subsurface equatorial upper ocean heat profile foreshadows phase change of various modes of climate variability. In the Indian Ocean, the eastern portion of the equatorial region has warmed significantly (Fig. 1). Implied is evolution of a potentially strong negative phase of the Indian Ocean dipole (-IOD). The daily IOD index is robust -1.04. The -IOD regime has arrived. In the equatorial Pacific, the eastern portion has cooled significantly. Implied is an approaching La Nina episode.

The Indian Ocean Dipole has shifted to negative phase and a borderline La Nina is developing. The last time -IOD and La Nina were present during SEP/OCT was in 2022 when buckets of rain fell on the East/Southeast! Be aware of potential over-achieving rains in the East for spring 2025! The AI Graph Cast week 2-4 outlook reveals the upcoming wet pattern for East Australia.

The North Atlantic basin SSTA is +0.28C which is quite cool compared to other years this decade. The 1-year change is -0.53C which is very impressive. However, there are basins which are very warm and capable of contributing to over-achieving tropical cyclones and their intensity. The Gulf of Mexico is near record warm (+0.90C) which is steady during the past 2 weeks. The Caribbean Sea is also very warm and unchanged during the past 2 weeks.