Retrospective: December-February 2019 Outlook

The atmospheric circulation around New Zealand was forecast to be characterised by higher pressure than normal extending from the Chatham Islands to the Australian Bight.

The atmospheric circulation around New Zealand was forecast to be characterised by higher pressure than normal extending from the Chatham Islands to the Australian Bight. Over New Zealand, the circulation was forecast to be characterised by westerly quarter flow anomalies and mixed flows. Actual pressures were lower than normal to the south of the country and near normal over New Zealand. As a result there was a slightly enhanced W-SW flow anomaly.

Predicted air temperature: December 2018 – February 2019 temperatures were forecast to be above average or near average for all regions of New Zealand.

Outcome: Actual temperatures were above average for the whole country.

Predicted rainfall: December 2018 – February 2019 rainfall totals were forecast to be near normal or below normal for the north of the North Island and near normal or above normal for the west of the South Island. Near normal rainfall was most likely for all remaining regions of New Zealand.

Outcome: Actual rainfall was near normal for many parts of the country. The exceptions were the West Coast, Tasman, Nelson, and Taranaki as well as parts of Southland, Wellington, Manawatu-Whanganui and Northland where rainfall was below normal. Summer rainfall was above normal for parts of Hawke’s Bay and coastal Bay of Plenty.