El Niño for Australia

El Nino likely to arrive over next three months: Australia weather bureau

Global Post,

3 December, 2014

SYDNEY (Reuters) - Climate models suggest El Nino weather conditions will occur over the next three months, although related weather patterns are already being witnessed, the Australian Bureau of Meteorology (BOM) said on Tuesday.

Climate indicators are close to El Nino thresholds, the BOM said, with models indicating a 70 percent chance of an event arriving by February.

El Nino is a warming of Pacific sea-surface temperatures that occurs every four to 12 years. It can trigger drought in some parts of the world while causing flooding in others.

The BOM said temperatures in the Pacific have already exceeded the El Nino threshold but the Southern Oscillation Index has yet to breach that level yet. The Southern Oscillation Index is a measure of Pacific air pressure fluctuations.

"Some El Nino-like impacts have already been seen this spring in Australia and several regions around the globe, including Asia, South America and southern Africa," the BOM said. "The Bureau's December–February Climate Outlook shows a drier and warmer summer is likely for many parts of Australia."

The dry weather is impacting Australia's agricultural production, with output in key commodities such as wheat set to fall as dry weather curbs yields.

Nearly all of the Australian east coast and South Australia received less than half the average amounts of rainfall over the last three months, denying crops much needed moisture.

El Niño-like impacts emerge in a number of areas

http://www.bom.gov.au/climate/enso/

2 December, 2014

Many climate indicators remain close to El Niño thresholds, with climate model outlooks suggesting further intensification of conditions remains likely. The Bureau’s ENSO Tracker status is currently at ALERT, indicating at least a 70% chance that El Niño will be declared in the coming months. Whether or not an El Niño fully develops, a number of El Niño-like impacts have already emerged.

Several ENSO indicators are currently close to, or exceed, El Niño thresholds. These include tropical Pacific Ocean temperatures, which have now exceeded El Niño levels for a month, and the Southern Oscillation Index, which has remained at or near El Niño levels for three months. Other indicators, such as tropical cloud, trade winds and rainfall patterns, have either remained near average or only temporarily approached thresholds. This indicates a typical El Niño ocean–atmosphere interaction may not be fully locked in.

The majority of international climate models surveyed by the Bureau suggest further warming of the tropical Pacific Ocean is likely, so it also remains possible that the ocean and atmosphere will fully couple in the coming weeks to months. If an El Niño is established, models suggest it will be weak, or moderate at most. Regardless of whether an El Niño is declared, El Niño-like effects are likely, as shown by the Bureau’s December–February Climate Outlook, which shows a drier and warmer summer is likely for many parts of Australia. Some El Niño-like impacts have already been seen this spring in Australia and several regions around the globe, including Asia, South America and southern Africa.


People will complain about a cool and windy summer in New Zealand. Look at the ocean temperature anomalies around New Zealand, a bit of an anomoly from the rest of the Pacific - cooler than usual.

Kiwis, be careful what you wish for this summer.

El Nino may be on its way to NZ

https://nz.news.yahoo.com/a/-/mp/25670043/el-nino-may-be-on-its-way-to-nz/

Hang on to your hats, the chances of an El Nino weather pattern sweeping New Zealand this summer have increased.

In its latest climate outlook for December through to February, Niwa says the equatorial Pacific Ocean has warmed significantly, reaching El Nino levels towards the end of November.

Some atmospheric indicators also show patterns consistent with the development of a weak El Nino.

"International guidance indicates that the chance for El Nino developing over the December 2014-February 2015 period is about 75 per cent," Niwa said.

"This figure has increased compared to forecasts issued last month."

For New Zealand, El Nino events have led to stronger, more frequent westerly winds, bringing droughts to eastern areas and more rain to western areas.

But Niwa says near normal rainfall is the most likely outlook for all regions of New Zealand over summer, with a significant chance of below normal rainfall (35 per cent) for the east of the North Island.

Summer temperatures are most likely to be average in all regions except the east of the North Island, where there's a higher chance of temperatures being above average.

Ocean forecast models indicate that sea surface temperatures are likely to be close to normal around the country over the next three months.

New Zealand has a slightly elevated chance of having an ex-tropical system coming within 550km of the country during the 2014-2015 tropical cyclone season, Niwa says.

The tropical cyclone outlook indicates this risk will be highest between February and April.

NZ: El Nino threatens to cool down season

NZ Herald

3 December, 2014

Weather forecasters say there is a high chance that a weak El Nino weather pattern will develop this summer, bringing cooler and windier conditions to the Bay of Plenty.

However, the Eastern Bay will be harder hit than Tauranga if the weather pattern does eventuate.

Niwa's seasonal climate outlook for December to February says there is a 75 per cent chance of an El Nino weather pattern developing.

In New Zealand, an El Nino system typically brings cooler, wetter conditions, with higher rainfall in regions that were normally wet, and often drought to areas that were usually dry.

Niwa National Climate Centre principal scientist Brett Mullan said if an El Nino pattern did develop, it would bring drier, cooler and windier conditions to the Bay of Plenty, but it would affect the Eastern Bay the most.

Dr Mullan said temperatures would not be particularly hot.

The report predicts an average summer, with temperature, rainfall and soil moisture measurements all expected to be near average.

Temperature had a 45 per cent chance of being near average and a 35 per cent chance of being above average.

Soil moisture has an equal chance of being average and below average.

Sea surface temperatures for the coming three months were expected to be near average around the coast.

Meanwhile, the short term weather forecast predicts a 25C high for Sunda