Thursday 25 October 2012

Forecasters surprised by El Nino turnaround


El Nino has meant drought dominated the Australian landscape until the big rains of the past few years. ABC TV, file image

The weather bureau is predicting a big change in Australia's weather forecast this summer, with an El Nino no longer expected.

Average rainfall is predicted in the coming months in the absence of El Nino - the climate pattern that brings drought-like conditions.

The chief climate forecaster says it is the biggest turnaround in weather patterns since records began.

In the 21st century, Australia's major weather pattern has been El Nino.

It has meant drought has dominated the landscape until the big rains of the past few years.

For climate forecasters, this summer was shaping up as deja vu, with the Bureau of Meteorology predicting another El Nino.

The bureau's manager of climate prediction services, Dr Andrew Watkins, has changed the forecast.

"Come September, all of a sudden, the temperature started to cool down, the trade winds started to become a little bit enhanced, and the cloud patterns and other indicators like that headed away from El Nino," he said.

"So this is what we're looking at as climatologists, giving us the heads up about what may happen over the next few months, and indeed what we're seeing now is a backing off from those El Nino thresholds."

Dr Watkins says they are not sure why there has been a cooling down.

"It actually is quite a unique situation if we end up not going into an El Nino event," he said.

"It'll sort of be the biggest turnaround that we've actually seen in our records going back to about 1950, so quite unprecedented."

Warming in the Pacific Ocean as recently as August pointed to another El Nino weather event, but the forecasters witnessed a huge turnaround.

While it is good news, they say they have never seen conditions change so quickly.

"When we go and look at our records of ocean temperatures in the tropical Pacific, we really haven't reached the level that we reached, say, in early September, and then turned around away from El Nino," Dr Watkins said.

"Every time we've got that close to an El Nino, it's actually settled in and indeed September, October is the normal time things bed down with these events.

"We actually haven't seen a turnaround quite like that."

No El Nino means it is more likely to rain across much of the country.

"And we're looking at actually increased likelihood of above-normal rainfall totals through much of the Northern Territory, northwest Kimberly and WA, and even into western Queensland as well," Dr Watkins added.
Grain of salt

But a lot of farmers take these sorts of predictions with a grain of salt.

Andrew Weidemann, the president of the Victorian Farmers Federation's Grains Group, runs a mixed farm in the state's north-west.

"The weather bureau tend to put out these predictions, but I guess in the farming sector what we deal with is results," he said.

"The results we're looking for are moisture at the critical times of the season to try and produce as much as we possibly can."

Much further north, the change is pointing to a good wet season in the vast grazing country across the Top End.

Northern Territory Cattlemen's Association executive director Luke Bowen says the forecast is good news.

"Good news for the monsoon region, given that there had been predictions that it was going to be a very, very late wet," he said.

"It's also potentially good news for those areas south of the tropic, where we've had a run of a couple of good years through central Australia, through the arid zone."

- ABC NEWS

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