Climate Update 41 - November 2002

November

Climate

River flows

Soil moisture

Three-month outlook

Checkpoint

Backgrounder

Backgrounder

Backgrounder

2002 rainfall to date
Much of New Zealand has received near normal rainfall. Parts of Waikato, Bay of Plenty, south Wairarapa, Marlborough, Nelson, and North and inland Otago have been drier than average. Parts of Manawatu, Westland, Southland, and south Otago have been wetter than average.

Total rainfalls for 1 January to 31 October 2002.
Update on the SOI
The mean Southern Oscillation Index (SOI) for October was -0.9, with the three month average now at -1.2.

Checkpoint

Outlook and outcome – August to October 2002
Rainfall was near normal, as expected, in parts of both main islands, but higher than predicted in the southwest of the South Island and lower than predicted in the north of the North Island, around Wellington, and in the east of the South Island.
Air temperatures were lower than predicted over the North Island. Pockets of the east and south of the South Island were warmer than predicted.
River flows were lower than predicted in the north of the North Island and in the north and east coast of the South Island.

Climate

New Zealand Climate
Coldest October since 1982
October received more than the usual number of cold snaps, keeping temperatures well below normal over most of New Zealand. The national average temperature was 1.1 °C below normal at 11 °C, the same temperature as that of September.
Overnight minimum temperatures were more than 2 °C below normal in many places.

November

Climate Update is a summary each month of New Zealand's climate, including soil moisture and river flows.
November 2002 – Number 41
October’s climate: The coldest October since 1982.

Three-month outlook

The outlook for November 2002 to January 2003
The moderate El Niño event in the tropical Pacific is expected to last through summer 2002-03, but is unlikely to be as strong as the 1997-98 event. Early summer climate in New Zealand is expected to be influenced by a continuation of lower than normal atmospheric pressures across southern New Zealand and episodes of stronger than normal westerly winds.
Temperatures are expected to be near average over the North Island and northern South Island, tending to below average over the rest of the South Island.

River flows

New Zealand River Flows
October streamflows mostly low
October flows were below normal in many areas, but near normal in the central North Island, the Tararuas, and Buller. Flows were above normal in coastal Southland.

Soil moisture

Soil moisture
East coast soils were generally drier than normal by the end of October. Particularly dry for this time of year were Hawke’s Bay, Marlborough, south Canterbury, and parts of coastal and inland Otago.