Retrospective: April-June 2018 Outlook
New Zealand’s regional climate over April – June 2018 was expected to be driven by persistence of more northeasterly airflow than normal. The northern Tasman Sea was expected to remain unsettled, with lower pressures than normal, bringing the likelihood of significant rainfall events to the North Island and the upper South Island. Actual pressures were much lower than normal across the country with more westerlies than usual for the North Island and more South westerlies for the South Island.
Predicted air temperature: April – June 2018 temperatures were forecast to be above average for all regions of New Zealand with high confidence.
Outcome: Actual temperatures were above average for most of the North Island and the Tasman district, while the South Island saw mostly near average temperatures.
Predicted rainfall: For April – June 2018, rainfall totals were forecast to be above normal in the north and east of the North Island, near normal in the west of the South Island, and near normal or above normal in all other regions.
Outcome: Actual rainfall was above normal for the majority of the North Island with the exception of the Far North, Taranaki and parts of Gisborne where rainfall was near normal. In the South Island, rainfall was largely near normal with the exception of Canterbury and parts of Marlborough, where above normal rainfall