Retrospective: February-April 2017 Outlook

With the likely persistence of ENSO-neutral conditions, and the anticipated absence of other large- scale climate drivers during February-April, the atmospheric circulation around New Zealand was expected to favour only slightly more westerly to south-westerly wind flows than normal. Actual pressures were slightly higher than normal over the South Island and lower than normal to the north west of the North Island. As a result, there were slightly more westerly to south-westerly winds than normal as forecast.

Predicted air temperature: February – April 2017 temperatures were most likely be near average for the north and west of the North Island and the east of the South Island. In the east of the North Island, temperatures were likely to be near average or above average, and seasonal temperatures were about equally likely to be near average or below average the north and west of the South Island.

Outcome: Actual temperatures were above average for virtually the entire North Island with the exception of the Greater Wellington Region where temperature was near average. In the South Island, temperatures were mostly near average. Pockets of above average temperature were recorded in coastal Westland, Grey, Buller and Hurunui districts.

Predicted rainfall: February – April 2017 rainfall totals were most likely to be below normal in the north and east of the North Island, and near normal or below normal in the west of the North Island. Rainfall totals were about equally likely to be near normal or above normal for the west of the South Island. Near normal rainfall was most likely for the north and east of the South Island.

Outcome: Actual rainfall was well above normal for the entire North Island as well as the north and east of the South Island. Rainfall was near normal in the Buller and Grey districts and below normal for the remainder of the west of the South Island.