27 JULY
THE NEW ZEALAND GAZETTE
2499

THE WEATHER IN NEW ZEALAND, MAY 1982

General—May was generally sunny and a little milder than usual. North-westerly winds were more frequent in the south, where there were also more strong winds than normal. Winds in the north of the country were unusually light.

Farmers in the North Island generally reported good late autumn pasture growth, but some eastern and southern areas were too dry to sustain much growth. Low rainfall also affected eastern areas of the South Island and led to reports of critical feed shortage from some districts. Heavy rain in parts of Westland and Southland this month led to pugging of pasture and slips on some properties.

A small tornado caused minor damage to out-buildings and trees in Otahuhu, Auckland on the 14th.

Rainfall—Apart from areas of Manawatu and Taranaki all of the North Island and the north and east of the South Island had less rainfall than normal for May. Eastern areas of both Islands were particularly dry, with some stations around Napier and Kaikoura recording less than 20 percent of their normal rainfall. Westland, Fiordland, Southland, and Otago were wetter than usual, with some areas to the south and inland recording twice their usual May rainfalls.

Snow fell to low levels in the South Island during the 22nd and 23rd, causing the closure of Lewis Pass and the Hope Saddle Road in Nelson and restricting traffic across Arthur’s Pass for a time.

Temperatures—Mean temperatures were above average by between 1° and 2°C in eastern and southern areas of the South Island and by up to 1°C for the rest of the South Island and northern and southern areas of the North Island. Central and eastern areas of the North Island were up to 1°C colder than usual.

There was a warm spell between the 7th and 11th during a period of westerly or north-westerly winds. Mean daily temperatures were up to 6°C above average at times and many stations, especially in the south and east and including Kaikoura, Christchurch, Dunedin, Alexandra and Roxburgh recorded maximum temperatures of 20°C or higher on one or more days during this interval.

Temperatures were again high in eastern areas between the 19th and 20th. During this period a maximum temperature of 24.6°C was recorded at Kaikoura, the highest for May since records began in 1964.

Sunshine—Sunshine hours were normal or above normal except in south Westland and Southland which had less sun than usual.

Some eastern areas were particularly sunny and Timaru recorded 171 hours, its highest total for May since 1938. Tauranga and Ruakura, with 188 and 173 hours respectively had their sunniest May since 1966 and Ohakea, with 164 hours, its second sunniest May since recording began in 1954.

Among those stations with the greatest departures this month were: Timaru (+52 hours), Ruakura (+45 hours), Tauranga (+43 hours), Gisborne (+44 hours), Hokitika (–37 hours), and Invercargill (–25 hours).

THE WEATHER SEQUENCE, MAY 1982

1st–7th May

On the first of May a shallow depression covered New Zealand and a cold front lying to the east of the country brought rain to northern and eastern areas. Light rain continued to fall in these areas on the 2nd as the depression moved eastward, while the rest of the country continued to have fine, cool conditions. An extensive anticyclone centred in the Tasman Sea extended a ridge onto the South Island on the 3rd and by the 4th lay centred over the South Island. Most districts had fine, settled weather during the 4th and 5th, apart from Northland, where there were isolated light falls of rain. Fine weather continued in many areas on the 6th but a front lying to the west of the country brought rain to Westland and Fiordland. Rain spread to Southland, Otago, Nelson, and New Plymouth on the 7th as a complex frontal system within a trough began to move onto the South Island.

8th–14th May

Rain became widespread on the 8th, as the trough moved onto the country, but had cleared from the North Island and east of the South Island by the 9th, although a disturbed westerly flow following the trough brought further rain to the rest of the South Island. Further fronts within this flow brought rain to southern and western areas of both Islands on the 10th and 11th. By the 12th a shallow but complex trough had developed in the south Tasman Sea, and rain fell in all districts except parts of Northland and Hawke’s Bay and the Kaikoura Coast as it moved onto the country. The trough developed into a depression centred over the South Island on the 13th and rain became widespread during the 13th and 14th.

15th–21st May

Rain cleared or became light in most districts as the depression moved off the country during the 15th. A south to south-westerly flow developed over the country between the 16th and 18th, bringing rain to Northland, southern and western areas of the South Island and night-time temperatures became cool. On the 19th an intense anticyclone crossed the north of the North Island resulting in a disturbed westerly flow over the rest of the country. Heavy rain fell in Westland, Fiordland, Southland, and the South Island high country. Temperatures were mild, particularly in eastern districts. Rain became widespread, apart from eastern areas of both Islands, on the 20th, with temperatures remaining mild. The rain eased or cleared from most North Island districts on the 21st, but remained heavy in all except eastern districts of the South Island.

22nd–31st May

A cold front associated with a depression near Macquarie Island crossed the country during the 22nd. Rain fell in all districts except east coast areas from Kaikoura north on the 22nd, and rain fell in the North Island and west of the South Island on the 23rd. A west to south-west flow developed behind this front, with further rain in central and northern areas of the North Island and the south and west of the South Island between the 24th and 26th. An anticyclone centred in the Tasman Sea began to move onto the North Island during the 27th, and, apart from isolated local rainfalls, there was a clearance in the weather. The anticyclone moved slowly onto the country during the last 4 days of the month, bringing fine weather to all districts.

(N.Z. Met. S. Pub. 107)

J. S. HICKMAN, Director.

Price 45c.

BY AUTHORITY: P. D. HASSELBERG, GOVERNMENT PRINTER, WELLINGTON, NEW ZEALAND—1982
844991—82PT