Global setting & climate outlook

Global setting

La Niña weakens further

Difference from average global SST (click to enlarge).

Monthly SOI values (click to enlarge).

The tropical Pacific is in a weak La Niña state at present, but conditions should ease to neutral by winter 2006.

Sea surface temperatures (SST) around New Zealand

New Zealand SST (click to enlarge).

Sea surface temperatures around New Zealand are close to average or above average and are expected to remain this way until May. The average SST anomaly at the end of February was about +1.0 °C, up strongly from +0.3 at the end of January.

Outlook for March 2006 to May 2006

Regional outlook (click to enlarge).

During autumn, atmospheric pressures to the east of the South Island are likely to be higher than normal, increasing the likelihood of northeasterly wind flows on to the North Island. Air temperatures are expected to be above average in the North Island and northern South Island, and average or above average in the rest of the South Island.

Rainfalls are likely to be normal or above normal in the east of the North Island, and normal or below normal in the eastern South Island. Elsewhere, near-normal rainfalls are the most likely outcome, apart from the northern North Island, where the outlook is unclear due to conflicting guidance from the suite of available prediction models.

Soil moisture levels and stream flows are likely to be below normal in the east of the South Island, and normal or below normal in the northern North Island. Normal or below normal streamflows are likely in the west and south of the South Island. Elsewhere, normal soil moisture levels and streamflows are likely.