A hotter and drier summer than normal in eastern Australia is looking a little more likely with the Bureau of Meteorology reporting today that the likelihood of El Niño remains high, with all climate models surveyed by the Bureau now indicating El Niño is likely to occur in 2014. Six of the seven models suggest El Niño thresholds may be exceeded as early as July.
The Pacific Ocean has been warming along the equator over recent weeks, with continued warming in the central Pacific likely in coming months. Another burst of westerly winds is presently occurring in the western Pacific, and is likely to cause further warming of the sub-surface.El Niño has an impact across much of the world, including below average rainfall in the western Pacific and Indonesian regions, and increased rainfall in the central and eastern Pacific. For Australia, El Niño is usually associated with below average rainfall, with about two thirds of El Niño events since 1900 resulting in major drought over large areas of Australia.
In Western Australia, where the Indian Ocean Dipole (IOD) is a major influence, the Bureau suggests, but not as strongly as for the eastern states, that lower rainfall than usual may be on the way.
Model outlooks currently suggest the IOD is likely to remain neutral through late autumn and early winter, with two of the five models surveyed suggesting a positive IOD may develop by early spring. Positive IOD events often coincide with El Niño and are typically associated with large parts of southern and central Australia experiencing lower rainfall than usual.
A couple of earlier stories by the Owl this month on El Niño: