Year of weather extremes causes havoc
It was a wild ride, with drought, storms, giant waves and a warmer than ever winter in MICHAEL DALY reports.
The sun shone on and on in the first months of 2013, but when the rain finally came so did ferocious winds. Drought was declared in Northland and northern Auckland in late-February, and the rest of the North Island joined in by midMarch.
A week later, declarations were made for the Buller and Grey districts in the northwest South Island.
In the worst drought in more than 65 years, pastures became desiccated, farmers were forced to sell stock, milk production fell, some farm incomes were slashed, and water supply restrictions were imposed.
‘‘Over the three summer months, most of New Zealand sweltered in record or near-record sunshine, while much of the North Island, Canterbury and Westland got less than half their normal seasonal rainfall,’’ Niwa said.
The drought was one of the most extreme on record for New Zealand, with the dry conditions unusually widespread. Worstaffected areas were southern Northland, South Auckland, Waikato, Bay of Plenty and the Central Plateau, Wairarapa, Rangitikei, Ruapehu, Gisborne, Hawke’s Bay and parts of the north and west of the South Island.
When records stretching back as far as the early 1940s were examined, they indicated the 2013 drought was similar in severity to one in the 1945-46 season.
Treasury calculated the cost of the drought to be about $1.5 billion in the 2013 calendar year.
In its March climate summary, Niwa said the month was ‘‘very dry’’ across the most of the North Island, and West Coast and Southland, and extremely sunny for the North Island and western South Island’’.
It was a desperate time. The sky was scanned for hints of moisture – and for most of the country there was deliverance. By the end of April Niwa was able to say: ‘‘The rainfall during April recharged soils throughout most of New Zealand.’’ The next month was also wetter than normal for much of the country, with Auckland having its wettest May on record – nearly 21⁄ times average at 261 millimetres.
Then, late in May, a cold southerly brought bone-chilling temperatures to many parts of the country. Snow was widespread over Southland, Otago, parts of Canterbury and the North Island’s Central Plateau. Winter had arrived.
Eastern and northern parts of the South Island received a drenching in May. In the middle of the month, 63-year-old Jude Hivon died when a huge landslide demolished her house at Sandy Bay north of Motueka.
The following month a storm making its way up the country smashed into Wellington. Severe gales blew over trees, lifted roofs, smashed windows, and knocked out power to about 30,000 homes.
The maximum 10-minute average sustained wind reading at Wellington airport was 101kmh, the strongest since 1985. The strongest wind gust was 143kmh, a record for June.
The storm was in the same category as five other major storms since 1961, but not as strong as the 1968 Wahine storm when the 10-minute average reading reached 144kmh.
On the Wellington south coast giant waves smashed houses, roads and seawalls, while inside the harbour the railway line to the Hutt Valley was undermined, with some track left unsupported. Tranz Rail chief executive Jim Quinn said the damage was ‘‘unprecedented’’.
Waves measured at a buoy two kilometres off Wellington’s south coast reached 15 metres high, the biggest waves since measurements at the buoy started in 1995. Anecdotal information put the height of the Wahine storm waves at 12m to 14m.
Powerful winds continued to batter the country in July, while August was less stormy, with well above average temperatures for most of the country. The highestever August mean temperature was recorded in 31 places around the country.
Heavy rain pelted Fiordland and the West Coast on September 10. Canadians Connor Hayes, 25, and Joanna Lam, 24, died when their rented campervan was hit by a landslide on the Haast Pass road and swept into the river below.
At the same time much of the South Island was blasted by strong northwest winds. Christchurch and Ashburton had their strongest September wind gusts on record – 133kmh and 128kmh respectively.
The wind left about 800 irrigators on Canterbury farms mangled and broken, while about 28,000 homes and businesses were without power throughout the region.
Wind and rain continued to knock parts of the country round through the rest of spring, although temperatures were often warm and some areas unusually dry and sunny. Highest-ever daily maximum temperatures for November were recorded in 21 places.
By the start of December, Niwa was warning that Northland, Auckland and Waikato were again much drier than usual for the time of year, while much of the South Island was also drier than normal.
For much of the North Island relief arrived early in December. Kerikeri did particularly well, receiving 185mm of rain in three days.
But after the experience the previous summer, farmers were doing little celebrating. Instead, they were looking ahead anxiously for the next spell of wet weather. They got some on Christmas Eve.