SOI remains in negative values (14/07/04)
Since the start of the month the 30day average of the SOI has stayed in negative values and as of the 14th July is minus 14.8. Despite this, for July to September there is a 50-70% chance of getting at least the long-term median rainfall for the southern quarter of Queensland. Rainfall probabilities across the rest of the state though are somewhat lower, with only a 30-50% chance of getting at least the long term July to September median rainfall.
It's also worth remembering that we are in our "traditional dry season" of July, August and September.
Given that rainfall for June across Queensland was very much below average to lowest on record, many producers are waiting for the next passage of the MJO. Unfortunately the last MJO in mid June had little impact on our weather. If its timing remains current it would next be expected in late July.
The MJO is simply 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 across much of Queensland.
Given the growing interest in the MJO, and with funding from the DPI&F, GRDC and CRDC we have developed a site http://www.apsru.gov.au/mjo/> that will allow anyone interested to track its passage.