Chance of Relief Rain
Dave McRae Qld Dept of Primary Industries and Fisheries 29th March
The MJO (or 40-day wave) is due in early April and will hopefully trigger some widespread and much needed relief rain. It can presently be found in the Indian Ocean and interestingly, has the strongest signal it has had for a number of months.
It is worth noting that this late in the summer rainfall season it would be unusual to see widespread monsoonal activity. However there is some potential for this MJO to trigger the development of a low-pressure system or tropical cyclone in the Coral Sea.
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) across much of Queensland.
For more information on the MJO including its location try www.apsru.gov.au/mjo or for more technical blurb try www.bom.gov.au/climate/tropnote/tropnote.shtml
If this MJO does trigger widespread rain it would prove a challenge to those producers with a large amount of sorghum and cotton harvesting to be completed.
The SOI has maintained a steady upward trend. As of Tuesday the 29th March the 30-day average was minus 2.2. This is up from minus 29.5 at the end of February. While still in negative values, at least it has returned to more favourable values.
Based on a 'Rapidly Rising' SOI phase over February and March, the chance of average to above average rain for April to June across most of Queensland is generally around 50%.
As we have stated regularly, for there to be an overall widespread improvement in conditions across the state, it would help if the SOI went into positive values for a couple of months at least. Daily updates on the SOI are available on (07) 46881439.
The latest rainfall probability maps for Queensland, Australia and the world are at www.dpi.qld.gov.au/climate or www.longpaddock.qld.gov.au For more information refer to the latest 'Climate Note' at www.dpi.qld.gov.au/climate or call the DPI Call Centre on 13 25 23 or (07) 3404 6999.