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.

Some forecast models have insisted that weak La Nina redevelops by quarter 4/2025. Diagnostics confirm the La Nina potential. During recent weeks a traditional cool phase Pacific decadal oscillation has formed, and the attendant atmospheric wind is driving cool waters off the U.S. West Coast toward the tropics south and southwest of Hawaii. Upper ocean heat has suddenly cooled. If the current trend persists, weak La Nina could emerge by northern hemisphere mid-autumn.

The Operational GFS and ECM forecast models are not projecting hurricane threats through their 15-day forecast period which brings us to August 4th without a hurricane so far during the 2025 season. Since 2018, the season’s first hurricane occurred prior to August 1st and during the 2016-24 active period (seasonal activity about 30% higher than the 30-year normal) the average date of the first hurricane is July 14th.

During the past 1-2 weeks, the Nino34 SSTA has cooled by more than 0.4C to -0.28C in the latest daily analysis. The La Nina threshold is -0.5C. Running parallel (and possibly related) to the Nino34 SSTA cooling is the vivid cool SSTA off the U.S. West Coast with that cooler water riding the California Ocean Current south and southwestward toward the tropics.