A year of climatic highs and lows

By PHILIP ENGLISH

Last year was one of the driest and warmest on record, but July was the coldest for 30 years.

Eight tornadoes swept through and storms produced hailstones the size of golf balls.

The year was one of weather extremes - and the indications are this year will be much the same.

Dr Jim Salinger, senior climate scientist with the National Institute of Water and Atmospheric Research, yesterday released the national climate summary for last year, saying climate records continued to be broken.

Temperature records were set locally and the year was bone-dry in many eastern parts of the South Island and in Wellington.

The national average temperature was 12.8 deg, 0.3 deg above the 1961 to 1990 norm, making the year one of the warmest on record.

The highest temperature was 35.5 deg, recorded at Timaru Airport on February 4, and the coldest - minus 12.2 deg - at Hanmer Forest on July 5.

The wettest place on record? No, not Milford Sound but the northern slopes of Mt Taranaki, where 7546mm of rain fell, driven by prevailing northerly winds. Milford Sound received 5134mm.

Auckland was not exactly the place for sunlovers. The area came in after Christchurch, Dunedin and Wellington as the wettest main centre. Wellington was the sunniest, followed by Christchurch and Auckland.

The sunniest areas were Nelson, Blenheim and Motueka.

The institute predicts the rest of summer - until the end of next month - will produce average or above average temperatures with near average rainfall in many places, but higher than average rainfall in the northern North Island.

Come autumn, though, there could be a change on the way, depending on what happens in the Pacific Ocean.

Dr Salinger said that last year one of the main annual influences on New Zealand climate, the cycle of El Nino or La Nina weather patterns, was in neutral.

He said the latest data from the tropical Pacific Ocean suggested that El Nino conditions could return later in the year. El Nino brought to New Zealand more westerly and southwesterly winds, making it wet in the south and west and drier in the north and east.

Dr Salinger said it was too early to tell, but if El Nino conditions returned, the warm sea that had surrounded New Zealand for some time might cool - also cooling air over the country.

Although it was impossible to use year-to-year records to show evidence of global warming, last year was consistent with global warming caused by greenhouse gas emissions, he said.

It was likely to be the world's second warmest year on record after 1998.

Global warming signs were present in New Zealand, where subtropical grasses were migrating south and frosts were less common than 100 years ago.

"Take a leaf out of nature," Dr Salinger said. "If we look around us, say in northern New Zealand, the warm season is longer. A tomato beetle, which was a pest in the Bay of Plenty, has now turned up in Hawkes Bay."