NIWA is forecasting moderate La Niña conditions in the period December to February in New Zealand.
Air pressure is forecast to be higher than normal over and to the southeast of the South Island and lower than normal to the northwest of the New Zealand bringing drier conditions across the country. Despite higher air pressure at the start of summer, NIWA expects moist, sub-tropical disturbances over the North Island and northern South Island, with systems expected to bring heavy rainfall with elevated humidity.
Rainfall is about equally likely to be near normal or below normal in the east and west of the South Island and about equally likely to be near normal or above normal in all remaining regions of the country. Extended dry spells may be interspersed with the expected unsettled periods. Soil moisture levels are about equally likely to be near normal or below normal in the west of both islands and the east of the South Island and most likely to be near normal in the north of both islands.