Outlook - October to December 2012
The Pacific Ocean is still close to El Nino thresholds, but the atmosphere has yet to show patterns typical of El Nino. The conditions are likely to remain close to thresholds or transition towards a weak and short-lived El Nino over the next three months. No signs of the enhanced southwesterly and westerly airflow over New Zealand that is usually associated with El Niño events however are forecast for the October – December season. Higher than normal pressures are expected South of Australia and New Zealand at the mid-latitudes, and lower pressures than normal are forecast to the north of the North Island.
Rainfall is likely to be near or above normal in the north and west of the North Island as well as in the north of the South Island, and near normal in the rest of the country.
Soil moisture and river flows are forecast to be above normal in the southwest of the North Island, near or above normal in the north of the North Island and north of the South Island, and near normal elsewhere.
October-December temperatures are forecast to be average or above average for all regions of New Zealand.