Commodities-Climate & Weather news; 2-week heavy rain alert for north Australia

Jan. 13, 2011
The prevailing La Nina event, blamed for triggering record-breaking rains over Australia, may be just peaking and is quite sometime away from a wind-down.
Northern Australia is likely to experience above average rainfall for at least another week or two, according to the Bureau of Meteorology (BoM), the national forecaster.
ACTIVE TROUGH
The potential for tropical cyclones to form in the surrounding seas will also remain at a moderate to high level whilst the Australian monsoon trough is active in the area.
La Nina refers to a cooling event in the central and east equatorial Pacific, with strong winds pushing warm waters towards Australia and the adjoining west Pacific.
The warm waters fuel convection and sets up thunder clouds, which in turn breed tropical storms and cyclones.
The December to March Australian monsoon is a successor event to its better known northern hemisphere counterpart, the Indian or Asian monsoon.
Studies have shown that preceding Australian conditions may have virtually had no significant correlation with succeeding Indian conditions.
But comparable Indian conditions have shown significant correlations with many succeeding Australian regional values.
For instance, India saw some heavy to very heavy rains batter the country in what was a linear extension of the very same La Nina conditions in the Pacific.
That such strong wet weather should have come virtually on the heels of a record-smashing drought underwritten by the year 2009 El Nino year had made scientists and researchers sit up and take notice.
Nobody had bargained for the scale and intensity of the rain fury unleashed over the continent in the far-east.
But researchers at the Tokyo-based Regional Institute for Global Change (RIGC) had flagged the possibility of ‘stronger than usual La Nina' well in advance.
And this is what has proved now, with the BoM itself saying in its latest update that a major La Nina event continues to affect the Pacific Basin.
Long-range models surveyed suggest that this event may be at its peak, and will persist into the southern hemisphere autumn.
But RIGC researchers are of the view that the event could last through the whole of this year even while progressively weakening and may peter out in 2012 only.
THIRD WETTEST
Previous strong La Nina events, such as those of 1974 and 1955, have also been associated with widespread and severe flooding in eastern Australia.
Sea surface temperatures off the Queensland coast in recent months have been at or near record levels.
The current event has contributed to 2010 being Australia's third wettest year on record, and Queensland having its wettest December on record.

Source: www.thehindubusinessline.com ByVinson Kurian,Thiruvananthapuram