Climate Update 48 - June 2003

June

Climate

River flows

Soil moisture

Three-month outlook

Checkpoint

Backgrounder

Checkpoint

Outlook and outcome – March 2003 to May 2003
Rainfall was near or below normal as expected in the east of the North Island and in south Canterbury and east Otago. It was wetter than expected in central and north Canterbury, and north of Auckland. Lower than predicted rainfall was recorded in western regions and in the south of the South Island.
Temperatures were near average as predicted in the east and far south of the country, but higher than predicted elsewhere.
Normal or below normal river flows were expected in most regions.

June

Climate Update is a summary each month of New Zealand's climate, including soil moisture and river flows.
June 2003 – Number 48
May’s climate: Warm in many areas.
May’s river flows: Improved river flows over the past month.
Soil moisture levels: soil moisture levels much improved.
Three month outlook: Mostly normal rainfall and above average temperatures expected over the next three months.
Checkpoint: How well are we doing with our predictions?
Backgrounder: Solar radiation – measurement and importance.

This issue of the Climate Update is available as a PDF.

Climate

New Zealand Climate
May temperatures above average
May was much warmer than average over most of New Zealand. The May national average temperature of 11.6 °C was 1.1 °C above normal, the warmest since May 2000.
Farewell Spit recorded its highest mean temperature (13.7 °C) since records began in 1971, while Hanmer’s temperature for the month was 2.2 °C above its historical May average.
The month’s climate was dominated by more frequent anticyclones ('highs') to the east of the North Island and southwest of Tasmania.

Three-month outlook

The outlook for June to August 2003
A mild winter is expected, with above average temperatures in all districts except the east of the South Island, where above average or average temperatures are expected. Despite this, some typical winter cold spells are likely, with frosty conditions in inland places.

River flows

New Zealand River Flows
Improved river flows over the past month
May streamflows were high in parts of Northland, Coromandel, the East Cape and the central Southern Alps and below normal in the southern North Island, south Canterbury, north & central Otago and Southland. Near normal flows occurred in most other locations.

Soil moisture

Soil moisture
Soil moisture levels much improved
Widespread rain and decreasing evapotranspiration rates in May lifted soil moisture levels in much of the country, with particularly improved conditions in the southern and central North Island. Otago and coastal Marlborough soil profiles contained less than normal available water at the end of the month.

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