Retrospective - November to January Outlook

Over the November-January (early summer) period, weakly enhanced southwest winds were (correctly) predicted over New Zealand. Higher pressures than usual were observed over the season over the Tasman Sea, with lower than normal pressures to the southeast of the Chatham Islands. 

Predicted rainfall: rainfall is likely to be near normal or below normal in all North Island regions and in Nelson-Marlborough, but near normal in other South Island regions.

Outcome: It was indeed a much drier than usual November-January period across most of the North Island. Less than 60 percent of the usual November-January rainfall totals were received for many North Island areas, the exceptions being coastal Gisborne, northern Northland, and from Taranaki to Wellington (where near normal seasonal rainfall was observed). It was also drier than usual in Marlborough, Nelson, northern Tasman District, Buller, and northern Westland. Above normal seasonal rainfall was recorded across much of Fiordland, Southland, Central Otago, north Canterbury, and along the Southern Alps. For the remainder of the South Island, near normal rainfall was recorded.

Predicted air temperature: Air temperatures for early summer are likely to be in the average or above average range in the north and east of the North Island, but near average in other regions.

Outcome: Across much of the north and east North Island, early summer temperatures typically straddled the threshold between average and above average, but were generally within 0.5C of the historical average elsewhere in New Zealand.