Retrospective - June to August Outlook

For winter (June–August) 2013 higher than normal pressures were forecast for the south and southeast of the country, with lower than normal pressures are expected to the west and north of New Zealand. This circulation pattern was expected to be associated with more northerly and north-easterly airflow than usual. Weak MSLP's dominated over New Zealand during winter with much higher than normal to the east and south-east of the country, and lower than normal to the north, west and south of New Zealand. As expected, more northerly and north-easterly airflow than usual occurred across most regions. Note that the neutral conditions (neither El Niño nor La Niña) were expected to persist over the June–August period. This forecast was well advised ongoing ENSO-neutral condition prevailing over the tropical Pacific.

Predicted rainfall: Rainfall is likely to be in the normal or above normal ranges in the north and east of the North Island, and near normal for the southwest of the North Island and for all the South Island.

Outcome: This rainfall forecast was mostly correct for the north and south-west of the South Island, as well as the east and northern most districts of the North Island. However, it was drier than expected across many central areas of the North Island including Taranaki, much of the Waikato and the Bay of Plenty where below normal rainfall was observed. In contrast, it as much wetter than expected for the season across much of the east of the South Island (particularly Dunedin City, Central Otago and the coastal strip between the Waitaki and Selwyn Districts).

Predicted air temperature: temperatures are very likely to be above average across the entire country.

Outcome: The forecast was correct for most regions of the country with temperatures more than 1°C above average across most of the South Island and southern parts of the North Island. Temperatures in excess of 1.5°C above average were also recorded across Southland and pockets of the Manawatu and Queenstown Lakes Districts. Notwithstanding this warmer than normal pattern, average temperatures were recorded in parts of the Waitomo, northern Thames-Coromandel, Auckland and Far North Districts.