For the past three months WeatherWatch.co.nz has maintained that La Nina should bring “healthy” rainfall to the upper North Island this summer – despite the incredibly dry spring.

Other forecasters agree, saying wetter weather may be on the way further down the track.

Yesterday on Radio Sport’s Farming Show weather analyst Philip Duncan told host Jamie MacKay that the big dry could very easily be washed out.  “Yes, it’s abnormally dry at the moment but La Nina summers often bring wetter weather to northern and eastern New Zealand”.

“We’re seeing sparks of life now in the tropics to the north and north west of us – once those warmer sea waters get closer to peaking as we head further in to summer then it’s possible we may be seeing the big dry turn into the big wet”.

Meteorologist Bob McDavitt has advised farmers to go back and check their farm performance data for 1989 because “this La Nina is currently closest to the seasons of 1975-1976, and 1988-1989,” NZPA reported yesterday.

He said that in 1989, January was so drizzly in Auckland that people became alarmed that similar weather might strike in the summer of 1990, when the Commonwealth games were due to be staged there.

“There may well be a deja vu of all this in January 2011,” said Mr McDavitt.

Philip Duncan says we need to watch the northern Tasman Sea and Coral Sea area.  “This is where our biggest rain makers often come from” and added that life has started to appear in the skies over these regions lately – and elsewhere.  “We’ve seen flooding in Queensland, rain in New South Wales and severe thunderstorms and flash flooding in Victoria., plus a tropical depression over Vanuatu 10 days ago.  The rain is there, it’s just been missing New Zealand due to persistent high pressure over us”.

But Mr Duncan did point out that our nation is small and vulnerable when it comes to big highs.  “Highs can easily cover our small country for lengthy periods – as they have done for two months now – which can severely limit rain.  I guess I’m cautiously optimistic that healthier rainfall figures will be reported in January”.

WeatherWatch.co.nz also urges farmers in very dry regions to still be prepared for possible droughts.  Mostly dry weather is still in the forecast for the next 10 days at least.

NIWA predicts average to above average rainfall for Northland and Auckland over the coming summer months.

A climate scientist, Bret Mullan, who wrote a paper on the influence of the La Nina/El Nino patterns on New Zealand weather, said that during the 1988-89 summer above-normal rainfall was experienced in the northern part of the North Island reported NZPA yesterday.

“Many places from Auckland northward received almost twice their normal summer rainfall,” he said. “January was a particularly wet month, with rainfall in these northern areas being three to five times normal.”

– WeatherWatch.co.nz, NZPA