19 OCTOBER
THE NEW ZEALAND GAZETTE
3441

THE WEATHER IN NEW ZEALAND—AUGUST 1982

General—August was generally a dry, sunny month that was slightly cooler than usual in the North Island but mild in the South Island.

In the north winds were generally lighter than usual and south-westerly winds were much more frequent than normal. South-westerlies were also very frequent in the south and Invercargill has its greatest frequency of both south-westerly winds and strong winds since 1964.

The dry, sunny conditions experienced in most districts suited lambing but farmers in drier areas, especially the Kaikoura Coast and mid-Canterbury, are experiencing feed shortages for stock. Snowfall in Southland on the 26th caused some stock losses.

Galeforce winds and thunderstorms were widespread on the 2nd as an active front crossed the country, and a tornado, at Netherton (near Paeroa) caused some damage locally.

Rainfall—It was a very dry month in the North Island, with most areas recording less than half their normal August rainfall. The driest areas were the Kaikoura coast, where between 10 percent and 25 percent of normal rainfall was recorded, and coastal Canterbury where between 20 percent and 50 percent of the usual month’s rainfall was received. Drought conditions continued in these areas, which have had only 50 percent to 70 percent of their usual rainfall for the year to date.

In the South Island most northern and eastern areas recorded less than half their normal August rainfall. August was relatively mild in the South Island, with most areas averaging temperatures about 1°C above normal with parts of Canterbury up to 2°C above normal. This was mostly due to high daytime temperatures, these being up to 3°C above average for the month. Some high temperatures were recorded during a warm spell between the 22nd and 25th. On the 24th 22.1°C was recorded at Ashburton 21.9°C at Timaru and 21.4°C at Hororata, the warmest August temperatures for over 10 years.

Sunshine—August was generally sunny, with the only areas to record less sunshine than usual being the west coast of the South Island and Southland. Eastern areas were particularly sunny, with Gisborne recording its highest August total since opening in 1937, Masterton its highest for August since 1937 and Christchurch its second highest for August since opening in 1949.

Among those stations recording high sunshine totals were: Gisborne (+52 hrs), Masterton (+47 hrs), Wellington (+44 hrs), Christchurch (+42 hrs), Napier (+41 hrs), Timaru (+35 hrs), and Kaikoura and New Plymouth (both +31 hrs).

THE WEATHER SEQUENCE—AUGUST 1982

1-7 August
A shallow trough lay over New Zealand on the 1st, with an associated weak frontal system lying to the west of the country. As this trough crossed the country rain fell in all districts, except those on the east of the South Island, on the 1st and over most of the North Island and south of the South Island on the 2nd. An extensive anticyclone, centred near Lord Howe Island had begun to spread onto New Zealand by the 3rd and rain cleared from most districts, although the ensuing south-westerly flow over the south of the South Island brought some showers to western areas on the 4th. Northern and eastern areas had light rain on the 5th and 6th and the passage of a cold front on the 7th brought isolated falls in some districts but the weather was otherwise fine and cool under the influence of high pressure across the country.

8-14 August
During the 8th and 9th an extensive anticyclone, centred close to Australia, covered the Tasman Sea and extended onto New Zealand, bringing generally fine, mild weather. Although this anticyclone still covered the North Island on the 10th a strong disturbed south-westerly flow developed over the South Island. A front within this flow brought heavy rain to the south and west of the South Island on the 10th with lighter falls over the North Island on the 11th. There was further rain in many parts of the South Island on the 13th as a second front crossed the country. By the 14th the anticyclone had moved away to the east and a trough moved onto the country, bringing light rain to many areas.

15-21 August
The trough and its associated front, which moved onto the country at the end of the second week, continued to bring light rain to many areas, particularly in the North Island as it moved eastward during the 15th and 16th. During the 16th a belt of high pressure extended across the country with strong westerly flows developing to the south. A cold front within the flow moved onto the South Island on the 17th and rain fell in southern and western areas of both Islands. There were some isolated light showers on the 18th but by the 19th the front had moved east of the country and a ridge from an anticyclone in the eastern Tasman Sea extended onto New Zealand. The weather became generally fine and cool during the next two days apart from isolated falls of rain in western areas of the South Island.

22-31 August
Although a belt of high pressure still extended over the North Island on the 22nd there was a disturbed westerly to south-westerly flow onto the South Island. A front within this flow brought heavy rain to Fiordland and Westland on the 22nd and lighter falls in other southern areas. A second, more extensive front brought further rain to western parts of the South Island on the 24th and there were heavy falls in most districts as this front crossed the country during the 25th. This rain cleared, apart from isolated light falls in eastern and central areas of the North Island, during the 26th as the front moved eastward off the country. Fine, cool weather continued as a ridge from an anticyclone over southern Australia extended onto New Zealand on the 27th, although there were some showers in Westland and Fiordland due to a front lying to the south-west. These showers spread into western and southern areas of both Islands on the 28th as the front crossed the country. Isolated showers continued in some districts on the 29th but the weather was otherwise fine. A complex trough began to move onto the country on the 30th, bringing heavy rain to Westland and Fiordland, and as this trough and an associated front moved eastwards rain spread over most of the South Island and the south of the North Island on the 31st.

(N.Z. Met. S. Pub. 107) J. S. HICKMAN, Director.

Price 45c
BY AUTHORITY: P. D. HASSELBERG, GOVERNMENT PRINTER, WELLINGTON, NEW ZEALAND—1982
88830J—82PT