Seasonal Streamflow Forecasts
Date: May to July 2012
The streamflow forecasts for the May to July period are favouring near median or high flows for the majority of forecast sites, with the exception of very low flows in the Loddon basin. Near median to very much above median streamflows were recorded in April at most of the forecast locations, with a record high April monthly streamflow at Biggara in the Upper Murray basin. Climate models surveyed by the Bureau suggest that the tropical Pacific Ocean will remain at neutral levels at least into early winter.
Click on the pie charts to go directly to the latest forecasts.
Victoria
Seasonal Streamflow Forecasts
for May to July
Southern New South Wales
Seasonal Streamflow Forecasts
for May to July
Northern New South Wales
Seasonal Streamflow Forecasts
for May to July
Note: The locations on the map are either site-based forecasts or total catchment inflow forecasts. Forecast site information provides details on which locations are site-based or total inflow forecasts. For more details about how the pie chart forecasts are displayed go to the Frequently Asked Questions.
Low forecast confidence for majority of sites - May to July
The forecast skill scores for the May-June-July period are moderate for seven of the thirty-six forecast locations. The forecasts for twenty locations have low skill and are displayed as faded pie charts on the maps. Skill scores for these forecasts exceed those obtained from using the historical record to calculate probabilities (historical reference). The forecast skill scores for the remaining nine locations are very low for this period and are displayed as grey pie charts on the maps.
April: Near median to very much above median streamflows, rainfall below average in south and close to average in north
After a very wet March in the south, April rainfall was average to very much below average over most Victorian and southern New South Wales forecast catchments and only slightly above average over forecast catchments in northeast New South Wales, the Shoalhaven River basin and far eastern parts of the Murrumbidgee River basin.
Averaged across each state, Victoria and New South Wales received 29 and 24 mm of rainfall respectively, well below their long-term averages of 51 and 47 mm. The Murray-Darling basin received an area average of only 14 mm of rainfall in April, less than half the long-term average of 38 mm.
Notably above median April streamflows were recorded at some forecast locations in the Ovens, Kiewa, Murrumbidgee and Upper Murray basins, with a record high April monthly streamflow at Biggara in the Upper Murray basin. Near median April streamflows occurred at Lake Nillahcootie, Taggerty and Willow Grove in Victoria, and Rocks Crossing in northern NSW. Very low April total inflows occurred at Cairn Curran and Tullaroop reservoirs in the Loddon basin in Victoria.
Climate indicators across the tropical Pacific Ocean remain neutral (neither El Niño nor La Niña). Climate models surveyed by the Bureau suggest that the tropical Pacific Ocean will remain at neutral levels at least into early winter. Some, but not all, climate models note an increased risk of El Niño conditions evolving during winter or spring. Historically, about 70% of two-year La Niña events are followed by neutral or El Niño phases. The Indian Ocean Dipole (IOD) has limited influence on Australian rainfall from December through to April. Model outlooks currently suggest neutral conditions are the most likely scenario heading into the southern winter.
For the latest ENSO Wrap-Up go to ENSO Wrap-Up.
For detailed information on Australia's climate go to Climate Information. For the rainfall outlook for the same forecast period go to Rainfall outlook for May to July 2012. For the latest rainfall outlook go to Rainfall outlook.
