14 OCTOBER THE NEW ZEALAND GAZETTE 4443

THE NEW ZEALAND WEATHER IN AUGUST 1985

In August it was drier and sunnier in most places with temperatures about normal.

South-westerly winds were more frequent than normal over the North and South Island but strong winds were less frequent than usual.

Mean sea level pressures were 2 hectopascals higher than average over New Zealand.

Most North Island farmers reported stock as being in good condition but grass growth was not as good as in June or July, due to the cooler weather. In Hawke’s Bay there was a lack of feed on some farms and in North Otago in the South Island topsoils have been dry with slow grass growth and some stock in poor condition.

Gale force northerly winds caused major disruptions to Cook Strait rail ferry crossings and aircraft passengers during the 19th. Airports which were either marginal or closed were Auckland, Palmerston North, Wellington, Nelson, Westport, Hokitika and Duedin. Some turbo-prop aircraft were grounded and nearly 4000 passengers held up.

Some maximum gust recorded were:
Auckland Airport 88 km/hr.
Dunedin Airport 85 km/hr.
Wellington Airport 132 km/hr.

A number of small tornadoes occurred due to an unstable westerly flow over Auckland on the 2nd. One was sighted to the west of Auckland, and another caused minor damage at Rotoroa Island. Another occurred on the 6th and took the roof off a deer shed and flattened 35 shelter trees, up to 25 metres high, on two farms near Hamilton at about 3.15 p.m. It left a 1–2 km long path of damage with a trail of no more than 100 metres wide in only a very short period of time. A short time after the tornado in Rukuhia an electrical storm accompanied by hail swept the Hamilton area. Hailstones were reported to be 7 to 8 mm in diameter, and in Cambridge hail was about 25 mm deep on some roads.

Snow fell to low levels in Canterbury and Otago during the 12th to 14th, and again in Otago on the 20th and 21st. South Island ski fields were closed on the 20th due to high winds.

Rainfall—Over the whole of the North Island rainfall was generally below normal. The only areas which received slightly above normal rainfalls were Taranaki and Wellington. Gisborne and Hawke’s Bay areas had below normal rainfall ranging from (19 mm) 22 percent of average at Napier Airport to 46 percent of average at East Cape. Gisborne was also rather dry with only (48 mm) 38 percent of average.

Over the South Island rainfall was below average in coastal regions and well above average in most inland high country regions. Oamaru received only (14 mm) 36 percent of average. To date this year Oamaru has had only 44 percent of the average rainfall.

Temperatures—Over the North Island mean daily maximum temperatures and minimum temperatures were slightly lower than usual ranging from between 0.0 to 0.5 C below average in most places. Night time temperatures averaged between 1.0 C to 1.5 C below normal in the Gisborne, Whakatane and Rotorua regions.

In the South Island mean temperatures were slightly warmer than average due to an increase in both mean daily maximum and minimum temperatures. Nelson and Marlborough were colder than average by about 0.5 C.

Some record or near record minimum air temperatures for August were recorded this month at the following stations:

Date Station Minimum Previous record
temperature
15 August Roxburgh –6.0 C –6.3 C in 1972
16 August Hamilton Airport –4.8 C –5.0 C in 1972
16 August Whakatane Airport –2.6 C –2.4 C in 1980

Whakatane had a mean daily minimum temperature of 2.4 C, this is the coldest for August at that station for over 10 years.

Sunshine—Sunshine hours were above average over the whole of the country apart from the lower South Island. In many western and central North Island regions and in the Bay of Plenty this was the sunniest August for over 10 years, while in the South Island at Invercargill Airport it was the least sunniest August for 10 years.

Among those stations which recorded the greatest departures this month are:
Christchurch Airport (+ 39 hours).
Ohakea (+ 38 hours, the highest since 1972).
Ruakura (+ 33 hours, the highest since 1961).
Stratford (+ 33 hours).
Invercargill Airport (– 30 hours, the lowest since 1975).

J. S. HICKMAN, Director.