The Australian Bureau of Meteorology says all indicators reflect a neutral ENSO situation, but says it remains possible that a La Nina event could develop later this year.
"In the tropical Indian Ocean, warmer-than-average ocean temperatures have persisted in the east, while in recent weeks, ocean temperatures in the western Indian Ocean have cooled slightly," notes the bureau. "As a result of this pattern, the Indian Ocean Dipole (IOD) index has been below -0.4 since mid-May. If this index remains at or below -0.4 until late July, 2013 will be classified as a negative IOD year. Four of the five models surveyed point to a negative IOD during the southern winter-spring period."