Seasonal Climate Outlook Message for January to April 2009

The bottom line

Bureau releases summary reports Dave McRae, Qld Climate Change Centre of Excellence, 19/01/09

The Bureau of Meteorology has recently released the annual Australian Climate Statement for 2008.

Key summary points include the mean Australian annual temperature for 2008 was the 14th warmest on record at 0.41°C above normal; above average annual rainfall was recorded across the Top End, eastern Queensland, northeast New South Wales and far west parts of Western Australia with average to below average rainfall throughout the rest of Australia including the southern Murray Darling Basin which further exacerbated the drought conditions experienced in that region. For more information go to www.bom.gov.au/climate/current/

According to the latest Bureau of Meteorology ENSO Wrap-Up (available at www.bom.gov.au/climate/enso) a neutral sea surface temperature (SST) pattern is persisting in the Pacific Ocean. Of interest however, is that a number of La Nina like characteristics can also be found. For example, the south east trade winds have been stronger than normal across the western half of the equatorial Pacific. This has contributed to the SOI remaining in positive values for the last few months and the inflow of warm moist air across the eastern Australian coastline.

Also subsurface ocean temperatures stretching from the central to eastern Pacific are cooler than normal. This would normally be considered as an early indicator for a developing La Nina SST pattern. This raises the possibility of reaching La Nina levels, even if only briefly, if the cooling persists.

Historically however, our climate year runs from autumn to autumn and it would be unusual for a La Nina (or that matter an El Nino) to develop at this time of year. This is reflected in the output from the reviewed dynamic climate models with the majority forecasting a neutral SST pattern to persist through to the end of the 08/09 summer.

The 30 day average of the SOI as of 19 January is plus 11.8. You can receive a text message with the latest SOI values sent to your mobile phone. To subscribe to this free service, call (07) 4688 1459.