Retrospective: June-August 2018 Outlook
The atmospheric circulation around New Zealand was forecast to be characterized by mixed flow patterns during June-August 2018. Periodic easterly-quarter (NE to SE) air flows were signalled during June which may give way to more westerly or southwesterly air flows during July and/or August. Actual pressure were lower than normal in the Tasman and near normal over New Zealand. There was no significant airflow anomaly.
Predicted air temperature: June – August 2018 temperatures were forecast to be near average or above average in the north and west of the North Island, near or below average in the east of the South Island, near average for all other regions of the country.
Outcome: Actual temperatures were near average for much of the North Island with the exception of the Greater Wellington Region and parts of Manawatu-Wanganui where temperatures were slightly above average. In the South Island, temperatures were near average for the north of the South Island and parts of Otago and Southland. Elsewhere temperatures were above average.
Predicted rainfall: June – August 2018 rainfall totals were forecast to be near normal or above normal in the north and east of the North Island and east of the South Island. Normal or below normal rainfall was forecast in the west of both islands with near normal rainfall expected in the north of the South Island.
Outcome: Actual rainfall was near normal across the North Island and the north and west of the South Island. Rainfall was below normal for the east of the South Island.