21 JANUARY THE NEW ZEALAND GAZETTE 83

WEATHER NOTES FOR OCTOBER 1980

General—Over most of New Zealand, October was a windy,
sunny, and mild month with below average rainfall. There was a high
frequency of north-west winds although in the north, north-east
winds predominated.

Good pasture growth and high dairy production were reported by
many farmers despite the below average rainfall. In the east of the
South Island spring crops had not been striking well because of
depleted soil moisture. During October areas of Canterbury had a
calculated soil water deficiency on at least 10 days.

The Milford Sound - Te Anau road was reopened to tourist traffic
by the middle of the month, after having been closed by avalanches
since mid-August.

Early in the month gale force winds fanned fires in Otago and
Canterbury. These caused the loss of about 8000 hectares of tussock
land in Otago and more than 1300 hectares of beech forest at Mount
Thomas Forest.

Rainfall—Rainfall was above average in Fiordland, the north of
the South Island about Manawatu, and in the far north of the North
Island. Elsewhere it was below average, and in some eastern districts
was less than 50 percent of normal.

During the 9th, localised heavy showers in the Dunedin area made
roads slippery and accidents were reported. Musselburgh reported
28 mm during the day, 9 mm falling between 2 p.m. and 4 p.m.
Portobello Road measured 26 mm, 11 of which fell between 2 p.m.
and 5 p.m.

Heavy rain during the 17th to 19th in the Manawatu area caused
some lowland areas to flood on the 18th and 19th. Rainfall totals for
the 17th to 19th included Fielding (57 mm), Bunnythorpe (47 mm),
Palmerston North (71 mm), Komako (74 mm), Haydon Street,
Palmerston North (75 mm), and Waipuna (79 mm).

Christchurch with only 12 mm of rain had its driest October since
1961. The total September-October rainfall of 13 mm was the lowest
recorded for these months at the airport since records began there in
1943. The combined September-October rainfall at Timaru (23 mm)
is the lowest total measured since 1954, and the third lowest total
since 1897.

At Paparua (Canterbury) 6 mm of rain was measured, this being
the lowest October total since 1954, and Otoko (Gisborne) with
24 mm, had the driest October since 1961.

The highest October rainfall at lowland stations in New Zealand
occurred at Milford Sound where 635 mm fell. Such a value occurs at
Milford Sound in at least two Octobers every three years.

Temperatures—October’s mean temperatures were above average
over most of the country. Many eastern districts were over 1.5°C
warmer than usual and both the mean maximum and minimum
temperatures were above average.

At Christchurch the mean maximum temperature of 20.0°C was
the highest since 1961, and this value has been exceeded on only one
other occasion (20.7°C) since records began in 1953. The extreme
maximum of 30.1°C occurring on the 27th was the highest (13.5°C
above the mean daily October maximum) October temperature ever
recorded at the airport.

At Onepoto (Lake Waikaremoana) the mean maximum
temperature of 16.7°C was the highest since 1963; on only 2 other
occasions since 1935 has this value been exceeded.

Sunshine—In northern districts, the Bay of Plenty, and in the west
and south of the South Island sunshine hours were below average.
Elsewhere they were above average, and areas of North Canterbury
had an excess of over 40 hours.

The largest surpluses were noted at Hanmer (48 hours),
Christchurch (44 hours), Kelburn (31 hours), and New Plymouth (25
hours). Largest deficits were at Kaitaia (26 hours) and Dunedin (28
hours). Hanmer had its sunniest October since 1961, the monthly
value of 232 hours being exceeded only twice.

DAILY WEATHER SEQUENCE FOR OCTOBER 1980

Embedded in a westerly airflow over New Zealand, a cold front
passed over the South Island during the 1st and 2nd bringing rain to
the west of the South Island, but mostly dry conditions persisted
elsewhere. Another cold front over the Tasman Sea moved on to
New Zealand on the 3rd. This front brought outbreaks of heavy rain
to Westland, Buller, inland Kaikoura, and southern North Island
districts. It became slow moving over northern districts on the 5th as
a depression formed in the north Tasman Sea, with heavy falls of rain
being recorded in Northland.

An intensifying anticyclone moved across the south Tasman Sea on
the 4th to reach southern New Zealand by the 5th. The anticyclone
lay east of the South Island on the 6th. Both the depression and
anticyclone moved slowly east. Apart from showers in Fiordland and
in the east of the North Island from East Cape to Cape Reinga dry
weather prevailed during the 6th and 7th.

A trough of low pressure accompanied by rain moved across the
Tasman Sea on the 8th reaching Fiordland on the 9th with heavy rain
being reported there. The trough lay over New Zealand on the 10th
and 11th and during this time light rain fell in most other districts.

An anticyclone over the Tasman Sea on the 11th extended a ridge
into the South Tasman Sea and a south-west airflow covered New
Zealand on the 12th bringing light showers to many areas. The
anticyclone and ridge moved eastwards as a depression moved on to
the Tasman Sea. The depression crossed the South Island during the
15th, and its associated north-south front brought rain to the country.
A ridge of high pressure behind the depression, moved on to the
South Island on the 16th, and lay to the east by the 17th. Meanwhile,
a depression moved north-east from south of Tasmania, and
deepened to lie over central New Zealand on the 18th, and near
Chatham Island by the 19th. This system brought rain to New
Zealand and localized flooding was reported in parts of Manawatu
during the 18th.

A large anticyclone centred in the south Tasman Sea covered New
Zealand on the 20th, and lay to the east of the North Island on the
21st. Dry weather covered the country except for a few showers in
Northland. A trough of low pressure formed near Norfolk Island on
the 21st and then moved east bringing rain to Northland.

A cold front over the Tasman Sea on the 21st moved over New
Zealand on the 22nd. Apart from local heavy falls of rain in
Fiordland, mostly light falls were recorded. An anticyclone in the
central Tasman Sea moved onto central New Zealand on the 24th.
The north-westerlies on the southern side of the high brought some
heavy falls of rain to Fiordland, but elsewhere dry weather persisted.
Another cold front with rain affected the south-west of New Zealand
on the 25th, but dry conditions prevailed as the front moved north-
east over the South Island and weakened. The front was followed by
an anticyclone, and by the 27th the main anticyclonic centre lay east
of Gisborne with a ridge of high pressure over New Zealand and the
Tasman Sea.

During the 28th and 29th a strong north-west airflow became
established over the country as the ridge of high pressure weakened,
and on the 29th a cold front spread onto New Zealand bringing rain
to most areas. Heavy falls of rain occurred again on the West Coast
during the 28th and 29th, some southern areas receiving more than
100 mm. As the front moved away to the east on the 30th, a disturbed
westerly airflow became established.

A trough of low pressure on this flow on the 31st brought frequent
showers and thunderstorms to the west and south of the South Island,
and scattered light showers to the west of the North Island.

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

J. S. HICKMAN, Director.

Price 25c BY AUTHORITY: P. D. HASSELBERG, GOVERNMENT PRINTER, WELLINGTON, NEW ZEALAND—1981