Global Setting – December 2012

The equatorial Pacific Ocean reflects ENSO-neutral conditions (neither El Niño nor La Niña). Global guidance indicates that these neutral conditions are very likely to persist into the Southern Hemisphere autumn. For the New Zealand region over the coming three months (January-March 2013), lower than normal pressures are expected in the south Tasman Sea and to the southeast of the Chatham Islands, with enhanced south-westerly winds over the country. 

Sea surface temperatures 

Sea surface temperatures around New Zealand are expected to remain close to average overall over the late-summer period. 

Differences from average global sea surface temperatures for 9th December 2012 to 7th January 2013. Map courtesy of NOAA Climate Diagnostics Centre (http://www.cdc.noaa.gov/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: December SOI -0.8; October to December average -0.1.
Differences from normal December surface temperatures in the seas around New Zealand.