The 2015/16 El Niño is showing signs of weakening, though this does not mean that the observed impacts seen across the Pacific islands will diminish right away. The effects of El Niño in many islands will continue to be felt through the remainder of the year.
The central Pacific Ocean surface and sub-surface temperatures have continued to cool. The Niño 3 indices in the eastern Pacific have declined, falling below the +2.0°C mark while Niño 3.4 and Niño 4 were nearly unchanged. In the atmosphere, the low-level westerly winds continued in the tropical Pacific at the 850 hPa level. The Southern Oscillation Index (SOI) has remained negative and collectively supports the view that El Niño has passed its peak and is on the decline.
The expected conditions from model predictions suggest that the El Niño decay will reach an El Niño–Southern Oscillation (ENSO) neutral state by June-July. Meanwhile, strong El Niño or remnants of the El Niño will remain through April. In the last half of the year the ENSO models predict a neutral ENSO rather than La Niña.
The seasonal forecast for the next three months has many of the islands in the southwest Pacific expecting drier than average conditions over the March to April 2016 period with the exception of Kiribati, Nauru and Tuvalu. Confidence in the forecast is Reasonable to High.
Deterministic Rainfall Forecast for March-April-May 2016 season, created by SPREP’s CLIKP.
The recorded impacts of the current El Niño includes:
a. Declaration of a Drought Emergency in the Republic of Marshall Islands
b. Declaration of a Meteorological Drought in Samoa
c. Heatwave in the Kingdom of Tonga
d. Fish kills reported in Vanuatu and Fiji
e. Coral bleaching across the Pacific
f. Active Tropical Cyclone season which includes Severe TC Winston (Category 5)
g. Frost and water shortage in Papua New Guinea