Another Summer Of Extremes
EXTREMELY DRY IN CENTRAL NEW ZEALAND, WET IN BAY OF PLENTY
COOL IN THE SOUTH, WARM IN AUCKLAND, BAY OF PLENTY AND
CENTRAL NEW ZEALAND
NELSON SETS NEW NEW ZEALAND SUMMER SUNSHINE RECORD
A 2000/2001 summer of climate extremes including droughts, floods and high humidity produced in Nelson a new seasonal sunshine record of 878 hours, 20 percent above normal and a new high for any New Zealand locality since such records began in 1930. Sunshine totals in Marlborough, Buller and north Canterbury were also at least 10 percent above normal. The national average temperature for the past summer of 16.8°C was 0.2°C above normal.
The extremely dry conditions
in central New Zealand – the third driest summer conditions
in parts of this region in 140 years of record keeping -
produced severe soil moisture deficits and very high fire
risk in Wellington, Nelson, Marlborough and Canterbury by
the end of summer. In contrast it was frequently wet in the
north east of the country.
The warm, dry and sunny
conditions throughout central New Zealand resulted from
more frequent highs (anticyclones) in the Tasman Sea, and
ridges well to the east of the Chatham Islands. At the
same time more lows (depressions) north east of Northland
caused the warm, wet and humid conditions in the north east.
More frequent westerlies to the south of the country kept
temperatures below average in southern New Zealand.
EXTREMELY SUNNY IN NELSON, LESS SUN THAN NORMAL IN AUCKLAND, THE CENTRAL NORTH ISLAND HIGH COUNTRY AND BAY OF PLENTY
It was extremely sunny in Nelson with a record
high total of 878 hours (20 percent above normal). The
earliest Nelson and New Zealand sunshine records commenced
in 1930. It was also sunnier than usual in Marlborough,
Buller, and north Canterbury, with totals at least 10
percent above normal. Record high summer sunshine was
recorded at Nelson, the highest in records going back to
1935. Hours of bright sunshine were below average in
Auckland, eastern Bay of Plenty, King Country and
EXTREMELY DRY IN CENTRAL NEW ZEALAND
Extremely low summer rainfall occurred throughout
Marlborough and Wellington where rainfall was less than 25
and 50 percent of normal respectively. Some areas within
these regions experienced their driest summer since that of
1907/08 – almost a century ago. Nelson was also very much
drier than average with totals less than 50 percent of
normal. Other regions with below average rainfall were
Canterbury and Taranaki, with totals between 50 and 75
percent of normal. Near or record low summer rainfall was
Paraparaumu, 96 mm 45% of normal, 2nd lowest in records back to 1945;
Kelburn, Wellington, 82 mm, 36% of normal, 3rd lowest in records back to 1862 (52 mm 1907/08, 78 mm 1886/87);
Wellington Airport, 71 mm, 37% of normal, lowest on record back to 1960
Wallaceville, 114 mm, 45% of normal, wnd lowest in records back to 1924 (106 mm in 1972/73);
Blenheim, 27 mm, 19% of normal, 2nd lowest in records back to 1902 (18 mm in 1907/08)
Winchmore, 99 mm, 57% of normal, 3rd lowest in records
back to 1947).
WET IN EASTERN BAY OF PLENTY
The summer was unsettled in Bay of Plenty (especially in the east), where rainfall ranged from 125 to 185 percent of normal. It was also wetter than usual in eastern areas of Northland, Coromandel, and parts of Waikato, Gisborne and Wairarapa with rainfall about 120 percent of normal. Near or record high summer rainfall was recorded at Whakatane with 382 mm, 147% of normal and 3rd highest in records back to 1975. Rainfall was near average over the remainder of the country.
WARM IN AUCKLAND, WAIKATO, BAY OF
PLENTY AND CENTRAL NEW ZEALAND, RATHER COOL IN THE SOUTH OF
THE SOUTH ISLAND
Above average temperatures occurred
throughout Auckland, Waikato, Bay of Plenty, Wellington,
southern Wairarapa, Marlborough and Nelson, all at least
0.5oC above normal.
Below average temperatures
occurred in Central Otago, and Fiordland, with mean
temperatures at least 0.5oC below normal. Elsewhere
temperatures were near normal.
The highest air temperature for summer was 35.3oC, recorded at Timaru Airport on the 4th of February. The highest February air temperature on record for this location is 39.8°C.
The lowest summer air
temperature was –2.8oC, recorded at Ranfurly on the 7th of
February after a clearance from cold southerly conditions.
The lowest February air temperature on record for this
location is -3.1°C.
High rainfall – floods
Severe thunderstorms occurred over Rotorua during the
early hours of the 8th of December, with spectacular
lighting for 3 hours, along with localized heavy rainfall
and surface flooding. Rainfall totalling 150 mm was
measured on a farm at Lake Rotoiti (in the Rotorua region).
A number of Masterton houses, shops and businesses were
flooded during heavy rainfall during thunderstorms on the
12th. Nearby, Carterton measured 70 mm.
westerly thunderstorm produced 246 mm of rainfall in 24
hours at Mt Cook over the Christmas period.
rainfall occurred in Coromandel on the 11th February, with
totals as high as 120 mm recorded at Whitianga, and at least
50 mm throughout much of eastern Northland, Bay of Plenty,
Waikato and Wanganui. Further high rainfall occurred in
Bay of Plenty and Gisborne on the 17th February, Whakatane
recording 130 mm.
Northeasterlies up to strong gale force broke windows at
an Akaroa property during the late afternoon on 13
Winds of up to 170 kmh from the south,
recorded at Taiaroa Head, Otago Harbour, lashed the South
Island on 16 January, causing power blackouts, blew fruit
off trees in Central Otago and yachts off their moorings.
Wellington was also battered by winds up to 140 kmh,
lifting roofs and bringing down power lines. A wind gust of
161 kmh was recorded at Puysegur Point, at the southwest tip
of the South Island.
Severe fires and drought
Severe grass fires, cited as the worst in the area since
European settlement, devastated about 7000 ha of grassland
in the Wither Hills/Awatere Valley area near Blenheim from
the 26th through 28th December. These occurred during
strong, hot and very dry northwesterlies. Temperatures of
near 30°C fanned the flames over the tinder dry region.
Between 2000 - 4000 sheep and 100 cattle were estimated to
have been lost due to the fires.
Severe soil moisture
deficits developed in Marlborough in December, and spread
to Nelson, Canterbury and Wellington by the end of summer.
Very low river flows had developed in the Nelson and
Marlborough districts by the end of February.
A sudden and violent hailstorm, lasting about 10 minutes occurred in the Masterton area about 6 pm on 7 January. Hailstones, some the size of golfballs (up to 4 cm in diameter) were reported. On two orchards all the apple and pear crops were lost, with severe damage to fruit in others. Over half the grapes were lost in one orchard. The severe hailstorm also broke windows and skylights, and damaged cars. The overall estimate of losses is $5 million.
Golf ball size
hailstones were reported at Alexandra on 8 January, causing
significant damage to some cherry crops.
For further information, please contact:
Dr Jim Salinger, NIWA - Auckland,
Tel (09) 375 2053 (Business) or (09) 527 3939 (after hours)
or Stuart Burgess, NIWA -
Wellington, (04) 386 0569.