Mostly Dry Conditions Persist (Dated 27/11/02)
Dry conditions persist across most of the state with little relief rain received over the past two months. Surface water supplies are a concern with many on-property storages, major water supplies, dams and bores dry or rapidly receding.
While the seasonal outlook for continuing hot and dry conditions across eastern Australia is not the best news for those regions looking for some relief, it is worth remembering that an El Nino does not mean there will be no rainfall at all. Changes in the SOI or sea-surface temperatures in the Pacific or Indian Oceans often mean some 'relief' rain can be received. However at present there is only a low chance of getting the well above average rainfall totals required to break the on-going drought.
An example of the below average rainfall totals received over the last 12-18 months is at Talwood. Talwood has a long term January to October average rainfall of 440mm. The total rainfall received this year for January to October at Talwood is 125mm. This is approximately 28% or less than one third of the long term January to October average rainfall.
The 30day average of the SOI as of the 27/11 is +0.1.
The 30-50day intra-seasonal oscillation (also know as the MJO) is simply a band of low atmospheric pressure that originates off the east coast of central Africa. It travels eastward across the Indian Ocean and northern Australia roughly every 30 to 50 days. While it is mainly a tropical phenomenon, it appears to indicate the timing of potential rainfall events (but not indicate rainfall amounts) over central and southern Queensland. It can help to enhance atmospheric activity such as upper level low pressure systems.
The use of the MJO as a reliable forecast tool is still at the research/experimental stage. The last passage of the MJO occurred in mid November as a fairly inactive event and did not help trigger any widespread rainfall events. It is next expected late in late December/early January. However at this stage the signal remains very weak.
Information from the Burea of Meteorology also suggests that the development of the northern Australian monsoon season is also unlikely to occur before Late December/early January.
The full December to February seasonal outlook will be issued next week. For more information try the DPI climate web site www.dpi.qld.gov.au/climate or call the DPI Call Centre on 13 25 23.