Global setting: February 2016

Strong El Niño conditions continued in the tropical Pacific during February 2016. Sea surface temperature anomalies still exceed +2oC in the central and eastern Pacific, but have cooled by 0.5°C or more from the peak values in November 2015.

The sub-surface ocean temperature anomalies in the eastern Pacific have decreased further since January, and anomalies of about +3°C are now confined to a layer above 75m east of 120oW. However, the Southern Oscillation Index has remained strong (near -2.0) during February.  

International guidance indicates that El Niño conditions will continue (99% probability) over the next three months (March – May 2016) as a whole, but weaken towards neutral conditions by the end of autumn. During winter (June – August), neutral conditions are likely to prevail (56%), whereas La Niña conditions are most likely to establish in spring (49%).

For March – May 2016, above normal pressure is forecast to the north and northeast of New Zealand, while below normal pressure is expected to the south of the country.  This circulation pattern is likely to be accompanied by anomalous northerly and north-westerly wind flows.

Sea Surface Temperatures

Sea surface temperatures around New Zealand are forecast to be above average, particularly to the west of the country.

Differences from average global sea surface temperatures for 31 January - 27 February 2016. Map courtesy of NOAA Climate Diagnostics Centre (http://www.esrl.noaa.gov/psd/map/images/sst/sst.anom.month.gif
Monthly values of the Southern Oscillation Index (SOI), a measure of changes in atmospheric pressures across the Pacific, and the 3-month mean (black line). SOI mean values: February SOI -1.8; December to February average -1.6.
Differences from average February surface temperatures in the seas around New Zealand.