CANBERRA, May 12 — Australia's Bureau of Meteorology (BoM) confirmed on Tuesday that El Nino thresholds have been reached in the tropical Pacific for the first time since March 2010.
Assistant Director for Climate Information Services Neil Plummer said El Nino is often associated with below average rainfall across eastern Australia in the second half of the year, and warmer than average daytime temperatures over the southern half of the country.
"The onset of El Nino in Australia in 2015 is a little earlier than usual. Typically El Nino events commence between June and November," Plummer said. "Prolonged El Nino-like conditions have meant that some areas are more vulnerable to the impact of warmer temperatures and drier conditions," he said.
Plummer said the failed northern wet season in 2012-13, compounded by poor wet seasons in 2013-14 and 2014-15, have contributed to drought in parts of inland Queensland and northern New South Wales.
Plummer noted that while the El Nino is forecast to strengthen during winter, the strength of an El Nino does not necessarily correspond with its impact on Australian rainfall. Australia experienced widespread drought during a weak El Nino in 2006-07, while stronger events such as the El Nino event in 1997-98 had only a modest impact on Australian rainfall.
"Recent significant rainfall and flooding along the east coast of Australia, associated with two almost back-to-back East Coast Lows, did not penetrate far into inland regions and therefore have done little to alleviate conditions in drought affected areas," he said.
While El Nino increases the risk of drought, it does not guarantee it. Of the 26 El Nino events since 1900, 17 have resulted in widespread drought.
Despite El Nino increasing the likelihood of drier conditions later this year, BoM's May to July Climate Outlook indicates much of Australia is likely to be wetter than average.
This is being driven by warmer than average Indian Ocean sea surface temperatures, which are dominating this outlook.(PNA/Xinhua)