Farmers Warned La Niña Not Over Yet

May 10, 1999

The global weather pattern that brought droughts to Otago and dry conditions in the Waikato appears likely to continue through winter and spring.

This is the key message in a Ministry and Agriculture and Forestry-commissioned report prepared by the National Institute of Water and Atmospheric Research (NIWA).

MAF is trialing the use of climate outlook information and advice from NIWA. With a better understanding of the outlook over a six to nine months future period, MAF is seeking to improve its agricultural forecasts for the following year. Also, the public release of climate outlook information is expected to assist risk management within the agribusiness sector.

NIWA National Climate Centre scientist Dr Brett Mullan said the La Niña event which has affected New Zealand's weather conditions since May last year has been slowly weakening over recent months. "But new information indicates that a La Niña resurgence is likely over the next six months," he said.

MAF senior policy analyst, Chris Ward, said this would not be welcomed by Otago's farmers who face the prospect of a third drought in a row coupled with low product prices.

"Clearly farmers, particularly in Otago and Canterbury, need to consider the possibility of drought when planning their finances for 1999/2000," Mr Ward said.

However it is still early days and there is a possibility that a renewed La Niña may not eventuate or that it may be weak.

The La Niña event has also been blamed for widespread facial eczema outbreaks in the North Island recently. Warm moist conditions promote the development of the disease.

Dr Mullan said that while there is considerable variability about New Zealand's weather patterns and it is not possible to predict the precise details, it is still possible to predict the changed odds of low or high rainfall over a season.

"By looking back at previous La Niña events, an indicative picture emerges for the coming seasons," Dr Mullan said.

"Over the winter, Central Otago is likely to get less rain than average while the North Island is likely to get average to above average rainfall. Temperatures will tend to be above average in the north of the North Island and below average in the Southern half of the South Island."

"During spring, eastern areas of the South Island are likely to get lower than average rainfalls but most of the North Island is likely to get higher than average rainfall. Temperatures are likely to be well above average."

"For summer and early autumn 2000, it is not clear what the state of the La Niña will be, but there is some chance that it may be an influence."

Finally, there is a positive side to the outlook for some regions, in that with the likely continuation of La Niña, her big brother the El Niño is very unlikely to appear over the next six months. The El Niño was the source of the 1997/98 droughts that badly affected east coast areas from Otago to Canterbury, Marlborough, Wairarapa and Hawkes Bay.

For further information contact:

Chris Ward, MAF, tel. 474-4168
Dr Brett Mullan, NIWA, tel. 386-0300



Last Updated: 10 September 2010

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