What the whole path means, place by place.
ENSO is a trajectory, not an event: the La Niña years since 2020, the eastern-Pacific El Niño building now, and a 2027–28 winter that could swing back. Each brief reads that path for one region: where it stands, what strong El Niños have done there season by season, what the models say, which reservoirs are running a deficit, what is compounding, and what to watch, with dates. Every sentence is generated from the site's data and carries its sample size and an evidence grade.
How the briefs are built
Each brief draws only on files this site publishes: the global drivers engine (strong El Niños since 1950 in each region's own season, with eastern-Pacific counts and states and provinces), the world model agreement (13 models through Jun–Aug 2027, each with its hindcast skill), the U.S. year-after composites (nClimDiv, run for each U.S. region as a whole), the trajectory analogs and the 2027–28 transition watch, the compound ledger of reservoirs since 2020, and the catalogue of compounding pathways. Counts are "k of n" with 95% Wilson intervals; an evidence grade tells how far each count is from chance. When an input has not been published, its section is left out.