Global setting & climate outlook

Global setting and climate outlook

La Niña on its way

 

Difference from average global SST (click to enlarge).

Monthly SOI values (click to enlarge).

Conditions in the tropical Pacific are currently neutral, although progressing slowly towards La Niña. The pattern of sea surface temperature anomalies resembles conditions that are typical of La Niñ, with colder than average waters in the far eastern Pacific and slightly warmer than average waters in the western Pacific. The SOI has risen in the last month to +0.4, and so is now more in phase with the oceanic part of ENSO than it was in earlier months.

Sea surface temperatures(SST) around New Zealand

 

New Zealand SST (click to enlarge).

Sea surface temperature anomalies in the New Zealand region increased in June, warming slightly to +0.8 °C, from +0.7 °C in May. The mean three month April to June anomaly was about +0.6 °C. SST anomalies have increased since April throughout most of the Tasman Sea, except for south of Chatham Rise to the east of the South Island, an area which remains cooler than normal.

Outlook for July to September 2007

 

Regional outlook (click to enlarge).

Atmospheric pressures at mean sea level are expected to be higher to the south or southeast of New Zealand, with more east or northeast winds than usual across the North Island.

Temperatures over land are likely to be above average across the country, with average or above average temperatures likely in the west of the South Island. Despite the overall temperature expectation, cold outbreaks typical of winter and early spring will occur from time to time.

Normal or above normal rainfall is expected in the north and east of the North Island, and normal rainfall elsewhere. Normal soil moisture and streamflows are expected everywhere except for the east of the South Island, where they are likely to be normal or below normal.