Climate Update 65 - November 2004

November

Climate

River flows

Soil moisture

Three-month outlook

Checkpoint

Backgrounder

Backgrounder

Backgrounder
‘A great wind is blowing, and that gives you either imagination or a headache.’
This observation, attributed to Catherine II, monarch, industrialist, scientist, and educator of the 18th Century, could as readily have applied to New Zealand as to her adopted Russia.
New Zealanders live in one of the windiest inhabited areas of the world, where the wind gives plenty of potential for both resource and hazard.

Checkpoint

Outlook and outcome – August 2004 to October 2004
Rainfall was near normal, as predicted, over much of the country, but drier than forecast in the north of the North Island and in parts of the west of the South Island. The south of the North Island, and parts of eastern and southern South Island, were wetter than predicted.
Air temperatures were lower than predicted in all regions.
River flows were lower than predicted in the north of New Zealand and in southern alpine regions.

Climate

New Zealand Climate
Low rainfall in the south
October rainfall was well below average in South Westland, Fiordland, and the Kaikoura coast. North Island rainfalls were higher, with above average rain in parts of Waikato, Hawke’s Bay, Bay of Plenty, and Wairarapa.
North Island air temperatures were mostly near or above average, while it was cool in Canterbury and Southland.
For more information on the climate in October, visit the climate summaries page at www.niwa.co.nz/ncc/cs/mclimsum_04_10
 
Percentage of average rainfall for October 2004 (recording sites shown with dots).

November

Climate Update is a summary each month of New Zealand’s climate, including soil moisture and river flows.
November 2004 – Number 65
October’s climate: Dry and cool in parts of the South Island; warm and wet in parts of the North.
October’s river flows: Central and southern North Island flows high.
Soil moisture levels: Soil moisture levels near normal.
Three-month outlook: A tendency towards normal temperatures and drier conditions in the north and east of the country; cooler and wetter in the west and southwest.
Checkpoint: How well are we doing with our prediction

Three-month outlook

The outlook for November 2004 to January 2004
Atmospheric pressure at mean sea level is expected to be lower than normal to the south and east of New Zealand, with stronger than normal west to southwest wind flows over the country.

River flows

River flows
Central and southern North Island flows high
Streamflows were above normal in the central and southern North Island. In the South Island, streamflows were below normal in alpine catchments south of the Grey and Hurunui Rivers. Elsewhere, streamflows were near normal.

Percentage of average October streamflows for rivers monitored in national and regional networks. The contributing catchment area above each monitoring location is shaded. NIWA field teams, regional and district councils, and hydro-power companies are thanked for providing this information.

Soil moisture

Soil moisture levels near normal
In most parts of New Zealand soil moisture levels at the end of October were near historical mean levels. In a few areas, particularly parts of Northland, Kaikoura, and east Otago, moisture levels were lower than average.
 
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). The analysis is done for an average soil type where the available water capacity is taken to be 150 mm.