Retrospective - June to August Outlook

Neutral conditions in the tropical Pacific were forecast to persist through much of winter, with a chance of El Niño developing by spring. This was an accurate prediction, in that threshold El Niño conditions now currently exist. Circulation patterns over New Zealand were forecast to be close to the seasonal norm, but this was not the case – a strong northeasterly anomaly affected New Zealand during winter, due to intense ridging (much higher than usual pressures) near the Chatham Islands.

Predicted rainfall: Rainfall totals are likely to be below normal in the eastern South Island, normal or below normal for Nelson/Marlborough, as well as the west and north of the North Island. Near normal winter rainfall totals are predicted for the South Island West Coast, and the eastern North Island.

Outcome: For the South Island above normal rainfall fell in Nelson, Marlborough, Canterbury and eastern Otago while normal to below normal rainfall was recorded for the West Coast and Southland, due to the frequent northeasterly events. For the North Island above normal rainfall fell in south Auckland, north Waikato, the Western Bay of Plenty and southern Hawkes Bay while below normal rainfall was recorded for parts of the Waikato, Taranaki, Manawatu and northern Hawkes Bay. Near normal rainfall observations were recorded elsewhere.

Predicted air temperature: Temperatures are likely to be near average overall for all regions of the country.

Outcome: Temperatures were above average for almost all coastal areas around the South Island. Parts of Manawatu, Taranaki, northern Hawkes Bay, western Bay of Plenty, south Auckland and Northland also recorded above average temperatures. Below average temperatures were observed over parts of south Hawkes Bay and northern Wairarapa. Near average temperatures were recorded elsewhere.