SOI in "Consistently Near Zero" Phase Dave McRae 12/02/07
There have been some very large rainfall events recorded across parts of northern and far western Queensland during January and February. However there are still plenty of locations especially throughout central and southern Queensland where a prolonged period of well above average rainfall is still needed to change the current drought pattern.
The monthly value of the SOI for December was minus 5.3 and for January was minus 8.9 which places the SOI in a "Consistently Near Zero" phase. Based on a "Near Zero" SOI phase and historical rainfall records, there is a 40 to 60% chance of getting median rainfall throughout Queensland for February through to the end of April. While the outlook is not as positive as many would like, it is an improvement from much of 2006 and as we are in our summer rainfall season there remains a reasonable chance of getting some useful relief rain. Daily updates on the SOI are available on (07) 46881439.
An MJO event moved eastward across northern Australia in early January. Evidence of this included the development of a tropical cyclone off the Western Australian coastline and enhanced convective activity towards the equator. Initially another MJO event was expected around the middle of February. However it appears that the next MJO event will be delayed until well into the second half of February.
The MJO is a band of low air pressure originating off the east coast of central Africa travelling eastward across the Indian Ocean and northern Australia roughly every 30 to 60 days. Research has shown the MJO to be a useful indicator of the timing of potential rainfall events (but not amounts). For more information try www.apsru.gov.au/mjo/