SOI Remains Near Zero (02/10/03)
The 30day average of the SOI has remained close to zero and as of the 2nd October is minus 0.7.
Based on this pattern there is a 40 to 50% chance of getting above the long term October to December median rainfall across most of Queensland. While these figures represent an improvement over this time last year, they are not high enough to guarantee immediate widespread drought breaking rain at this stage. For better chances of seasonal conditions improving the SOI needs to return to more sustained positive values.
Many people like to follow the timing of the MJO (also know as the 40day wave). The MJO is simply a band of low atmospheric pressure originating off the east coast of central Africa travelling eastward across the Indian Ocean and northern Australia roughly every 30 to 50 days.
While it is a tropical phenomenon, it appears to indicate the timing of potential rainfall events (but unfortunately not rainfall amounts) over central and southern Queensland.
The next passage of the MJO is expected to influence our weather over the coming week.