Indian Ocean reinforcing El Niño for October

The Australian Government  Bureau of Meteorology has today issued a mid-cycle update to its Climate Outlook for October to December 2015, as a result of rapidly evolving changes in key climate drivers in the oceans around Australia.

Bureau of Meteorology Climate Prediction Manager, Dr Andrew Watkins, said the Bureau monitors its rainfall and temperature model outlooks very closely.

“Since we released the Climate Outlook, there has been a significant shift toward a drier October for much of Australia. It’s highly likely this is related to a rapidly strengthening positive Indian Ocean Dipole,” said Dr. Watkins.

“We have been watching the waters to Australia’s northwest for signs of sea surface cooling that could reinforce the impact of the current strong El Niño. We are now seeing these signs, and their impact has been reflected in the most recent model outlooks for October.

“Recent upgrades to the Bureau’s Climate Outlook service have provided the capability to issue more frequent updates in exceptional circumstances, and we urge all stakeholders who rely on these outlooks in their planning to monitor our website for further updates,” he said.

The Bureau has recently upgraded its climate outlook service to enable special updates when necessary. An update of the October and October–December climate outlooks has been issued due to a significant shift in the October outlook nation-wide, related to a strengthening positive Indian Ocean Dipole reinforcing the impacts of the strong El Niño.

Climate outlook overview

• A special update of the climate outlooks has been released due to a significant shift towards a drier October nation-wide, related to the emerging positive Indian Ocean Dipole reinforcing the strong El Niño.
• September rainfall was third driest on record for Australia. Very low rainfall has been received over the past 12 months in the southwest of Western Australia, southeast South Australia and most of Victoria.
• Due to changed conditions in the tropical Indian Ocean and the strong 2015 El Niño, the rainfall outlook for October has shown a significant shift towards a drier month nation-wide, with the southeast quarter of Australia indicating a less than 20% chance of exceeding median rainfall for the month. This means the region has a greater than 80% chance of a drier month.
• The October rainfall outlook is accompanied with high chances of warmer days and nights south of the tropics.
• October to December is likely to be drier than average across the southeast and northeast, with parts of central Australia likely to be wetter than average. Warmer days and nights are likely for Australia, except the northern tropics.
• The current outlook reflects a combination of a mature El Niño in the Pacific, and an emerging positive Indian Ocean Dipole.