The Australian Bureau of Meteorology says tropical Pacific Ocean temperatures have approached or exceeded values commonly associated with the early stages of an El Niño event, however atmospheric indicators of ENSO such as trade winds and cloud patterns have yet to reach El Niño thresholds. To be considered an ENSO event, climatologists look for signals that indicate the ocean and atmosphere are reinforcing each other (i.e., “coupled”), and hence will be sustained over several months.
“Regardless of the ENSO state, the tropical Pacific remains warmer than average,” says the bureau. “This, combined with other influences on Australian climate such as cooler-than-normal waters to the north of the continent and the patterns of cloud and ocean temperatures in the Indian Ocean, tends to favor below-average rainfall over eastern Australia.”
Climate models surveyed by the Bureau of Meteorology suggest sea surface temperatures in the tropical Pacific Ocean will maintain values close to, or greater than, typical El Niño thresholds before returning to neutral towards the end of 2012 or early 2013.
Juli says: If this assessment is accurate, then this pending El Nino event will be short -- too short to have a lasting impact on the weather patterns.
