December 2018 was characterised by slightly lower than normal pressure over the North Island and higher than normal pressure over the South Island.
New Zealand Climate Update 235 - January 2019
11 January 2019
What happened in December, how our climate outlook for the previous three months turned out, global and local sea temperatures, and our outlook for January-March.
Over the past month, sea surface temperatures (SSTs) in the central Pacific (NINO3.4 Index, 5°N-5°S, 170°W-120°W) have remained above normal with anomalies currently exceeding +0.8°C. This marks the fourth consecutive month SST anomalies in the central Pacific have exceeded 0.7°C, which meets NIWA’S technical oceanic definition for El Niño.
January – March 2019 temperatures are forecast to be above average (50% chance) for the north of the North Island and above average or average (40 – 45 % chance) for all other regions of New Zealand.
The October – December 2018 atmospheric circulation around New Zealand was forecast to be characterized by higher pressure than normal to the west and southwest of New Zealand.