July 2025 monthly Pacific decadal oscillation (PDO) index was the most negative (-4.00) in the 1950-2025 climatology. The record -PDO was produced by the relationship between near to slightly cooler than normal sea surface temperature anomalies (SSTA) off the North America West Coast and the marine heatwave (MHW) excessive warm SSTA off the East Asia Coast and past the Dateline to 150W longitude.

The FINAL Climate Impact Company 2025 North Atlantic basin seasonal tropical cyclone forecast indicates (after Tropical Storm Dexter) that an additional 12 tropical cyclones will form of which 7 become hurricanes and 4 reach major hurricane strength. The accumulated cyclone energy (ACE) index forecast is 135.

A sophisticated analog system, the machine learning AI 4Cast Net V2 GFS ENS, projects above normal wind speed risk (at 100 meters) in the Gulf of Mexico to the Bahamas for middle August and across the Caribbean Sea for late August. Implications for potential tropical cyclones are suggested by these forecasts.

To help generate new season 1-4 ahead global climate forecasts, a constructed analog projection (through 2027) for ENSO, PDO, AMO, and IOD is revealed. The ENSO outlook indicates weak La Nina potential for Q4/2025 coupled with -IOD which supports wet Australia climate. The tendency of ENSO toward weak La Nina increases risk of significant tropical cyclone activity in the North Atlantic basin during AUG/SEP/OCT. The longest -PDO on record will continue possibly changing character to cooler Northeast Pacific SSTA (which promotes La Nina). The AMO regime stays warm through 2027.