Global setting and climate outlook

Global setting and climate outlook

La Niña likely to develop

Difference from average global SST (click to enlarge).
Monthly SOI values (click to enlarge).

Conditions are currently neutral in the tropical Pacific, but there is a relatively high (55%) probability of a transition to La Niña conditions over the winter period. The pattern of sea surface temperature anomalies, shown in the global map left, is beginning to resemble La Niña conditions, with colder than average waters in the far eastern Pacific off the north west coast of South America, and slightly warmer than average waters in the western Pacific.

Sea surface temperatures around New Zealand

Research Subject: 

New Zealand SST (click to enlarge).

SST anomalies in the New Zealand region continued to increase, rising in May to 0.7 °C above normal, up from 0.4 °C above normal in April. SST anomalies have increased since April throughout most of the Tasman, except for south of Chatham Rise to the east of the South Island, which remains cooler than normal. SST in the New Zealand region are expected to remain above normal over winter.

Outlook for June to August 2007

Regional outlook (click to enlarge).

Mean sea level atmospheric pressures are expected to be higher than average to the south of the South Island for the coming season, but lower than average over and west of the North Island.

Air temperatures are likely to be above average in all regions except for average or above average in the east of the South Island. Nevertheless cold outbreaks typical of winter will occur from time to time.

Normal or above normal rainfall is likely in the north and east of the North Island, with normal or below normal rainfall in the east of the South Island, and normal rainfall elsewhere. Below normal soil moisture levels and streamflows are likely in the east of the South Island, and normal or below normal soil moisture levels are likely in the west of the North Island. Elsewhere, normal soil moisture and stream flows are likely.