The equatorial Pacific Ocean remains warmer than normal, especially around and west of the Dateline, but the atmospheric conditions continue to be near neutral. Global guidance indicates that continuing neutral conditions are the most likely outcome over the next three months (December-February). In the New Zealand region, lower than normal pressures are expected southeast of the Chatham Islands, with enhanced south-westerly winds over New Zealand. For this tropical cyclone season (November – April), the risk of an ex-Tropical Cyclone approaching New Zealand is expected to be near normal. On average, one ex-Tropical Cyclone nears New Zealand during the season.
Sea surface temperatures
Sea surface temperatures around New Zealand are currently about 1 degree colder than normal, and are expected to continue below normal over the summer period.
Differences from average global sea surface temperatures for 4th November to 1st December 2012. 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: November SOI +0.3; September to November average +0.2.
Differences from normal November surface temperatures in the seas around New Zealand.