December rainfall outlook
MetService expects the top half of the North Island and the west coast of both Islands to receive below normal levels of rainfall for the month of December.
The south-east corner of the South Island and from New Plymouth to Wellington is expected to receive close to normal rainfall.
The west coast of the South Island is expected to receive more rain than normal for December.
The ocean
The El Nino conditions that have been experienced over the last few months have been comparable in strength to the 1997-98 and 1982-83 events. The MetService said this recent event may be approaching its peak with latest sea temperatures in the central tropical Pacific (the NINO3.4 region) being maintained at 3 degrees celcius above normal.
The Southern Oscillation Index rose sharply over the last two weeks crossing into neutral territory for the first time since July. It is typical of the index to bounce around at this time of the year so the effect on the weather in New Zealand should be minimal.
MetService said that climate models predict El Nino will weaken in the first quarter of 2016, and should transition to ENSO-neutral status by winter. Seas around New Zealand continue to be cooler than usual.
