Climate Watch Dave McRae Qld Dept of Primary Industries and Fisheries 26/04/05
Given the limited useful rain over spring and summer across much of Queenslands winter cropping area, soil moisture status at time of planting this year will be a major constraint.
Over the last 6-months most of Queensland has received less than 60 to 80% of average rainfall. For example, over the 6-months from October 2004 to March 2005, Dalby has recorded 290 mm of rain. This compares to its' long term average for those 6-months of 455 mm, which is a shortfall of 165 mm (or 6.6 inches in the old scale). This in the lowest 10% of rainfall recorded historically at Dalby for this 6-month period.
This lack of useful rain is reflected in the current soil water status in many cropping areas. Looking at the aggregated soil water status in the cropping regions as at 31 March 2005 ranked relative to all years (1901 to 2004 with a fallow simulated from 1 October) most of Queensland has a below average ranking in terms of aggregated soil water status with some regions such as surrounding Dalby being in the lowest 10% and surrounding Roma and Kingaroy in the lowest 20%.
Given the potential for an El Niño to develop later this year, an awareness of current soil water status should be part of management strategies in case the likelihood of usual in crop rainfall decreases. In terms of planting rain, the next "climate induced" opportunity should be with the passage of the MJO due in mid to late May.
For more information on the current soil moisture status as projected by the APSIM model contact Andries Potgieter from APSRU/DPI&F on (07) 4688 1417
The 30-day average of the SOI continues to fluctuate and as of the 27th April has dropped back in negative values to minus 9.5. Given the potential for an El Niño to develop later this year, it will be very interesting to see if a 'Consistently Negative' SOI phase pattern develops over the next couple of months.
The seasonal outlook for May to July will be released next week. In the mean time for more information on the current seasonal outlook try www.dpi.qld.gov.au/climate or call me through the DPI Call Centre on 13 25 23 or (07) 3404 6999.