Retrospective: November-January 2017 Outlook
The circulation pattern expected for November-January for New Zealand was broadly consistent with a typical La Niña signature: higher pressure than normal was forecast to the south and southeast of the country, while lower pressures than normal were forecast to the north of the New Zealand, leading to more persistent easterly or north-easterly airflow than normal. Actual pressures were lower than normal over New Zealand and particularly low south of the country. This pressure set up produced more south-westerly winds than normal across the country
Predicted air temperature: November 2016 - January 2017 temperatures were most likely to be above average for all regions of New Zealand.
Outcome: Actual seasonal temperatures were near average for much of the North Island with the exception of the New Plymouth, Stratford, Ruapehu, Waitomo, Otorohanga and Waikato districts where temperatures were below average. Small pockets of above average temperature were found in coastal Gisborne and Hawke’s Bay. In the South Island, temperatures were largely below average with the exception of Nelson, Marlborough and costal Canterbury where temperatures were near average.
Predicted rainfall: November 2016 - January 2017 rainfall totals were about likely to be above normal or near normal throughout the North Island. In the north and east of the South Island, rainfall was most likely to be near normal, whereas rainfall in the west and south of the South Island was about equally likely to be near normal or below normal.
Outcome: Actual rainfall was below normal for the north and east of the North Island and largely near normal for the west of the North Island. Pockets of above normal rainfall were observed in the Wellington Region as well as Porirua, the Kapiti Coast and South Taranaki. In the South Island, rainfall was above normal along the West Coast, Tasman, Nelson and eastern Otago.