Retrospective – September to November Outlook

During September-November 2014, mean sea level pressures were forecast to be lower than normal to the north as well as over most of the country. This pressure pattern was expected to be accompanied by generally anomalous easterly flow and perturbed conditions.

Actual mean sea level pressures for the forecast period were lower than normal to the south of the Chatham Islands, extending over the country, while higher pressures than normal affected the north Tasman sea, this resulted in strong westerly quarter flow anomalies over much of the country.

Predicted rainfall: Rainfall is likely to be in the near normal range for the north of the South Island, normal or below normal over the west of the South Island and normal or above normal in the remaining regions of New Zealand.

Outcome: Actual rainfall was well-below normal in the east and north of the South Island (40 to 60% of normal). Rainfall was also below normal in parts of the North Island including Tauranga, Western Bay of Plenty, Waitomo, South Waikato and the Kapiti Coast. Normal rainfall was experienced elsewhere.

Predicted air temperature: Temperatures are forecast to be most likely average for the east and west of the South Island, and likely average or above average for all remaining regions of New Zealand. Cold snaps and frosts can still be expected in some parts of the country as we advance into spring.

Outcome: Actual temperatures were mostly average (between - 0.5^oC and + 0.5^oC) over the whole country, with isolated pockets of below normal (less than -0.5^oC) temperatures in the Waitomo, Tararua and Dunedin districts.