The International Research Institute (IRI) for Climate and Society assembles a collection of dynamic and statistical ENSO phase forecast models on the third Thursday of each month and the latest update is indicated in Fig. 1. The consensus of the forecasts trends toward La Nina more quickly (mid-to-late northern hemisphere summer) and with stronger intensity for the last third of 2016. Interestingly, 3 dynamic models indicate super La Nina for the last third of 2016. Also of interest is that the dynamic models are generally stronger with La Nina later this year while statistical models range from neutral ENSO to weak La Nina. The influence of La Nina on global climate awaits the last third of 2016.
Fig. 1: A collection of dynamic and statistical ENSO phase forecast models by IRI is indicated.
The leading diagnostic foreshadowing ENSO phase ahead is the trend in subsurface temperatures in the equatorial Pacific region (Fig. 2). In April so far, a strengthening massive anomalous cool zone has stretched across the subsurface equatorial Pacific representing plenty of fuel to cause and intensify a La Nina episode once trade winds in the lower atmosphere strengthen and up-well the cooler waters.
Fig. 2: April (so far) analysis of subsurface temperature anomalies across the equatorial Pacific. The strengthening cool anomalies foreshadow La Nina ahead.
As reminder the La Nina influence on global precipitation and the timing of those regimes is convened by the IRI (Fig. 3). Generally, the influence of La Nina on global precipitation patterns is opposite of El Nino.
Fig. 3: Global influence of La Nina on precipitation patterns is indicated.