We’d like our forecasts—both weather and climate—to be simple and certain. Because of the fluid and chaotic nature of the ocean and atmosphere, however, forecasts are never about certainty: they’re about probability.
Chances that an El Niño will occur by summer are above 70%, hitting 80% by the fall. But subsurface temperature anomalies have tapered off some from earlier this spring, decreasing the odds the event will be as strong as the El Niño of 1997-98.
Though ENSO is a single climate phenomenon, it has three states, or phases, it can be in. The two opposite phases, “El Niño” and “La Niña,” require certain changes in both the ocean and the atmosphere because ENSO is a coupled climate phenomenon. “Neutral” is in the middle of the continuum.
The Pacific ENSO Update is a bulletin of the Pacific El Niño-Southern Oscillation (ENSO) Applications Climate Center, providing information on climate variability for the U.S.-Affiliated Pacific Islands. This newsletter is intended to supply information for the benefit of those involved in such climate-sensitive sectors as civil defense, resource management, and developmental planning in the various jurisdictions of the islands.