Outlook - November 2013 to January 2014
Atmospheric indicators of ENSO continue at near neutral levels.
International guidance indicates that the tropical Pacific Ocean is very likely to remain neutral over the next three months (November-January). Lower pressures than normal are forecast in the Tasman Sea and across the North Island, and higher pressures than normal are expected to the south of the country. Temperatures are equally likely (40% chance) to be near average or above average in all regions of New Zealand, except for the west of the North Island where near average temperatures are the most likely outcome (45% chance). Rainfall for the November-January period as a whole is likely to be normal or above normal in the north of the North Island, and near normal for all remaining regions.
November–January rainfall is forecast to be most likely (45-50% chance) near normal in all regions except for the north and east of the North Island, where rainfall is equally likely (40% chance) to be near normal or above normal.
November-January temperatures are equally likely (40% chance) to be near average or above average in all regions of New Zealand, except for the west of the North Island and east of the South Island, where near average temperatures are the most likely outcome (45% chance).
Soil moisture levels and river flows are most likely (45% chance) to be below normal in the north of the North Island, and most likely (50% chance) to be above normal in the east of the North Island, and likely to be near normal for all remaining regions.
For the tropical cyclone season (November – April), the risk of an ex-Tropical Cyclone (ETC) approaching New Zealand is expected to be close to normal. Based on the long-term record, ETCs come within 550km of New Zealand for 9 out of every 10 years (averaging close to one event per year). These systems typically occur during the latter part of the TC season (February–April). For ENSO-neutral years, ETCs are twice as likely to pass to the east of Auckland than west of the city.
