Global Setting – July 2013

The equatorial Pacific Ocean as a whole remains in a neutral state (neither El Niño nor La Niña) despite the persistence of colder than normal Sea Surface Temperatures (SSTs) in the eastern equatorial Pacific. International guidance indicates that ENSO-neutral is the most likely outcome for the next three months (August–October). For the New Zealand region, higher pressures than normal are forecast south of the country, while lower pressures than normal are expected to the north over Australia and the Coral Sea. This circulation pattern is expected to produce a weaker than normal westerly flow over the country. 

Sea Surface Temperature 

Sea surface temperatures are forecast to be above the climatological average for the coming three months along the east coast of New Zealand and further offshore, with conditions near average to the west and in the Tasman Sea. 

Differences from average global sea surface temperatures for 30th of June to 27th of July 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: July SOI +0.8; May to July average +1.0.