Climate Update 53 - November 2003

November

Climate

River fllows

Soil moisture

Three-month outlook

Checkpoint

Backgrounder

Backgrounder

Electron microscope photo of the dinoflagellate, Karenia brevisulcata, responsible for mass marine life mortality and contributing to human respiratory syndrome during the 1998 toxic episodes in Wellington Harbour.

Major harmful algal blooms (HAB) recorded from 1950 to 2002: S, nuisance “slime” events; A–I, other major harmful algal events. IPO phases are marked.

Checkpoint

Outlook and outcome – August 2003 to October 2003
Temperatures were lower than expected in most districts. East Cape, Westland, and Fiordland recorded temperatures close to those predicted in the outlook.
Rainfall was higher than expected in the eastern and northern North Island, and much of the eastern South Island. It was drier than expected in eastern Southland. Elsewhere it was mostly as predicted.
River flows were higher than expected in most North Island regions.

Climate

New Zealand Climate
A month of two halves
October was wet and unsettled in many areas for the first two weeks, and mainly dry and settled for the rest of the month. Westerly winds were less frequent than usual. Rainfall was well above average in some areas, particularly Northland, Coromandel, Bay of Plenty, south Wairarapa, and Wellington. It was below average in Hawke’s Bay, south Canterbury, Central Otago, Westland, and Fiordland.

November

Climate Update is a summary each month of New Zealand's climate, including soil moisture and river flows.
November 2003 – Number 53
October’s climate: October was sunny and cool. The month started wet but was dry and settled from mid month.

Three-month outlook

The outlook for November 2003 to January 2004
Rainfall is expected to be normal or below normal for the eastern North Island, and normal or above normal for the western South Island, with normal rainfalls elsewhere.

River fllows

New Zealand river flows
October streamflows were above average for many North Island rivers, apart from some streams in the Bay of Plenty and southern Hawke’s Bay. South Island streamflows were near average in Nelson, Buller, Marlborough, south Canterbury and North Otago; above average in north and mid Canterbury; and tended to be below average in central Otago and the west and south of the South Island.

Soil moisture

Soil moisture
Soil moisture levels near average
For most of New Zealand, soil moisture levels were near the historic average. However, at the end of the month, much of Otago had less than 50% of normal storage. Some parts of Central Otago were particularly dry, with conditions similar to those of October 2002.

Soil moisture deficit in the pasture root zone at the end of October (right) compared with the deficit at the same time last year (centre) and the long-term end of October average (left).