Dannevirke: El Nino puts council on early drought alert

Dannevirke may experience another drought this summer.

Concerns about a potential dry summer and El Nino in the district have prompted the Tararua District Council to make plans to put weather updates on its website.

And Councillor Jim Crispin believes the big dry is here already.

"I've never seen the farming district looking so dry at this time of the year," he said. "I'm seriously worried about this."

Councillors have been told there is concern about the strong El Nino weather pattern that formed some months ago in the Pacific Ocean. Fuelled from the difference in ocean temperatures, east to west, across the mid-Pacific, the mass of warm water in the Pacific Ocean is bigger and deeper than it was at the same point in 1997.

"Forecasters don't know the effect but, at a depth of 75 metres, the temperature is 28C to 29C across vast areas of the Pacific," Peter Wimsett, the council's manager of strategy and district development said. "In the good old days you might have expected those temperatures down to between 20 and 30 metres, but now we've a heat sink and what forecasters haven't seen before are the 30C blobs off the west coast of the United States and Canada. This is quite concerning."

A report to councillors states the available energy for an El Nino event is potentially high when compared to the worst recorded events since records began in 1950, with the impact on New Zealand's east coast having the potential for a dry summer.

However, Mr Wimsett said it will depend on whether the trade winds reduce or strengthen over the coming months. Less wind allows the ocean heat to rise and heat the air temperature.

"It will be in two months' time when forecasters have a far better handle on it, but I prefer our farmers to be alerted early," he told the Dannevirke News.

Norsewood weather watcher Lyn McConchie said, looking at her rainfall figures for the past four years, they are slightly lower than average but she cannot see a drought in her neck of the woods.

"I don't think we're about to plunge into a drought, but it depends on the area of the Tararua you are farming in. Areas out towards the coast become drier than we do here under the Ruahine Ranges."

Ms McConchie said that on Friday rainfall figures for upper Norsewood in August stood at 96mm and she was expecting more rain over the weekend.

"That's a little on the low side of average, but I've records showing rainfall figures from 73mm to more than 200mm for August out here."

While she regularly cross checks her rain figures with a resident living 20km away in a lower area, Ms McConchie said the rainfall is similar.

"But as you go further out to the southeast of the Tararua, things change.

"The Tararua has a number of micro-climates but in this area we're getting a solid rainfall.

"I'm not a meteorologist, but in light of my own experience and the records I keep, I'm pretty sure I know what to expect.

"In 1989, when I was looking for land to buy in this area, I looked at 50 places in a month during a serious Tararua drought.

"When I walked on to here it was knee-high in grass, probably because we get showers coming off the Ruahine Ranges, which sometimes just stop at my boundary."