Three-month outlook

The outlook for March 2005 to May 2005

Below average sea-level pressures are expected over the New Zealand and Tasman Sea region, with slightly enhanced southwesterly air flows across the country.

Air temperatures are expected to be average or below average in the North Island and near average in the South Island.

Rainfalls are likely to be normal or below normal in the north and east of the North Island and near normal elsewhere. Normal soil moisture conditions are expected throughout the country apart from normal or below normal in the east of the North Island. Normal streamflows are expected throughout the South Island, with a tendency to normal or below normal in the north and west of the North Island, and to below normal in the east of the North Island.

The tropical Pacific is in a weak El Niño state, but should ease to neutral conditions by May.

 

A. Climate models give no strong signals about how the climate will evolve, so we assume that there is an equal chance (33%) of the climate occurring in the range of the upper, middle or lower third (tercile) of all previously observed conditions.

B. There is a relatively strong indication by the models (60% chance of occurrence) that conditions will be below average, but, given the variable nature of climate, the chance of average or above-average conditions is also shown (30% and 10% respectively).