Retrospective: May-July 2018 Outlook

For May-July, the atmospheric circulation around New Zealand was forecast to be characterised by lower than normal atmospheric pressure through to July.  This was expected to result in mixed and changeable air flows across the country. Actual pressure were slightly higher than normal to the northeast of the country and lower than normal to the southwest of the country with no wind anomalies.

Predicted air temperature: May – July 2018 temperatures were forecast to be above average in the north of the North Island and average or above average for all remaining regions of New Zealand.

Outcome: Actual temperatures were near average for much of the country. Slighter higher than average temperatures were observed in parts of Gisborne Hawke’s Bay and Canterbury.

Predicted rainfall: May – July 2018 rainfall totals were forecast to be above normal in the north of the North Island, near normal or above normal for the rest of the North Island as well as the east and north of the South Island.  Normal or below normal rainfall was expected for the west of the South Island.

Outcome: Actual rainfall was largely near normal in the North Island with the exception of the Wairarapa where rainfall was below normal and parts of Auckland and Whangarei where rainfall was above normal. In the South Island rainfall was below normal for large parts of Canterbury, eastern Otago and eastern Southland while Tasman and Marlborough saw above normal rainfall. The remainder of the South Island observed near normal rainfall.