- ENSO = the El Niño/Southern Oscillation
- ENSO Neutral = the ocean surface temperature anomaly in the ENSO 3.4 region is between +0.5°C and -0.5°C.
- El Niño/La Niña conditions exist when the anomaly is greater than (Niño) or less than (Niña) the half-degree cut-off for neutral.
- A full blown El Niño/La Niña is declared when the conditions persist for three overlapping three-month periods i.e. five consecutive months.
IRI ENSO Forecast
2017 May Quick Look
Published: May 18, 2017
A monthly summary of the status of El Niño, La Niña, and the Southern Oscillation, or ENSO, based on the NINO3.4 index (120-170W, 5S-5N)
Use the navigation menu on the right to navigate to the different forecast sections
By mid-May 2017, the tropical Pacific remained in an ENSO-neutral state, with above-average SSTs present in the eastern Pacific Ocean, and near-average SSTs across the central and east-central part of the basin. The collection of ENSO prediction models indicates increasing chances of El Niño into the summer and fall of 2017....MORE
- El Niño and La Niña events tend to develop during the period Apr-Jun and they
- Tend to reach their maximum strength during October - February
- Typically persist for 9-12 months, though occasionally persisting for up to 2 years
- Typically recur every 2 to 7 years