SOI message 23rd February 2000
The average SOI over the previous 30 days is +12.6 . Based on the SOI, the probabilities of exceeding median rainfall during the total February to April period are little different from the 'normal' for this time of year in most of the eastern States of Australia, and 60-70% in many coastal districts of Queensland and New South Wales.
Based on the latest values and trends of the SOI, the probabilities of receiving above-median rainfall over the total February-April period are little different from the 'normal' for this time of year in most of the eastern States of Australia. Exceptions are most coastal districts of Queensland, western Cape York Peninsula, parts of far central-western Qld and the southern Maranoa, much of coastal NSW, south-western corner of NSW and far eastern Tasmania where probabilities are 60-70%.
The persistent 'cool' sea-surface temperature (SST) anomalies in the central and eastern equatorial Pacific Ocean, combined with 'warm' SST anomalies around northern and western Australia, suggest a mature La Nina pattern.
Forecasts from experimental general circulation models are currently suggesting that by mid-year the La Nina will have subsided and neutral conditions will dominate. However, sub-surface sea temperatures to the east of Australia are now significantly warmer than normal, in classic 'pre-El Nino' mode. In addition, some early research work suggests the sub-tropical ridge may again be further north than normal this winter which may tend to reduce winter rainfall from the Goondiwindi district through to the Central Highlands. As these indicators provide some cause for concern, regular monitoring of them and the SOI over the next few months is recommended.
Combining the rainfall outlook with current soil water and pasture condition, the probabilities of above-median pasture growth during the total February-April period are 60-90% in much of north Qld, central-western Qld, and far central-western Qld.
The next passage of the 30- to 50-Day Oscillation is expected about the first week in March.
More detailed information for your location can be obtained from the Australian Rainman software package. Also a lot of additional information is available on our FarmFax system, our Internet World Wide Web service called 'The Long Paddock', and on BoM's Fax and internet information services.
Information contained in this publication is provided as general advice only. For application to specific circumstances, professional advice should be sought. The Department of Primary Industries, Queensland, has taken all reasonable steps to ensure the information in this publication is accurate at the time of publication. Readers should ensure that they make appropriate inquiries to determine whether new information is available on the particular subject matter.