Outlook - February to April 2013

Conditions in the tropical Pacific are neutral (neither El Nino nor La Nina). While the equatorial SSTs in the eastern Pacific are currently slightly cooler than normal, they fall within the neutral range and all atmospheric indicators are close to their climatological values. The global forecast models indicate a very high likelihood (~ 95 %) of ENSO-Neutral conditions to persist into the autumn 2013. In the New Zealand region, slightly higher than normal pressures are expected south of the country as well as southeast of the Chatham Islands, with weak anomalous flow from the north-easterly quarter over the country. February-April temperatures are likely to be average in all regions but for the north of the North Island, where average or above average temperatures are expected. Sea surface temperatures are expected to be near average around New Zealand. Rainfall is likely to be near normal for all regions but for the North of the North Island, where normal or above normal rainfall is forecast. For this tropical cyclone season (November – April), the risk of an ex-Tropical Cyclone approaching New Zealand is expected to be near normal. On average, one ex-Tropical Cyclone nears New Zealand during the season. 

Rainfall is likely to be near normal for all regions but for the North of the North Island, where normal or above normal rainfall is forecast. Soil moisture levels and river flows are likely to be near normal levels for all of New Zealand for the season as a whole. 

February-April temperatures are likely to be average in all regions but for the north of the North Island, where average or above average temperatures are expected.

The return to near normal soil moisture levels will take some time for those parts of Northland, Auckland and the North Island east coast that are currently very much drier than usual.

For this tropical cyclone season (November – April), the risk of an ex-Tropical Cyclone approaching New Zealand is expected to be near normal. On average, one ex-Tropical Cyclone nears New Zealand during the season.