Seasonal Streamflow Forecasts

Date: October–December 2017



  • Near-median and low streamflows likely to dominate for October to December
  • Low and near-median flows observed at 82% of locations in September
  • El Niño–Southern Oscillation and Indian Ocean Dipole remain neutral

Streamflow forecast for October–December


For October–December 2017, near-median or low streamflows are more likely at 69 and 63 locations, respectively across Australia. High flows are expected at 15 locations, evenly split between the northern and southern mainland Australia. Almost two-third of locations (117) have moderate to high forecast skill for this time of year, while 36 locations have low skill.

Forecasts have not been issued for 34 locations due to very low model skill or missing observed data. We suggest using the observed climatology for these locations.

Use the map below to zoom and pan to view the forecast locations. Zoom in to view pie chart tercile forecasts, and then click on a pie chart to go directly to the latest forecast.

Note: The locations on the map are either site-based forecasts or total catchment inflow forecasts. 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.

Information video



Outlook video


  • Legend image demonstrating moderate to high skill

    Moderate to high skill

  • Legend image demonstrating low skill

    Low skill or missing climate data

  • Legend image demonstrating very low skill

    Very low skill or missing antecedent condition data


September catchment conditions

Low streamflows were recorded at 106 locations, mostly in the eastern states–including eastern Tasmania, with some in southwest Western Australia. Near-median and high flows were recorded at 43 and 25 locations, respectively across the country.

September rainfall was below average in most of New South Wales, Victoria and southern parts of Queensland, with New South Wales and the Murray–Darling Basin receiving the lowest September rainfall in record, and Queensland receiving the lowest since 2003. However, rainfall totals were above average in South Australia, most of the western part of Western Australia and southern parts of Northern Territory.

Actual evapotranspiration (ET) was below average in most of New South Wales, South Australia and southern Queensland, roughly coincident with drier soils. Evapotranspiration was above average in northern parts of the Northern Territory with smaller patches of above-average ET being observed in most of Western Australia and in southern half of Victoria. Modelled lower-layer soil moisture (10–100cm) was below average in most parts of New South Wales, South Australia, and central and southern Queensland. However, lower-layer soil moisture was above average in small parts of central and western parts of Western Australia and central parts of the Northern Territory

For more details on September rainfall across Australia, read our Monthly Climate Summary. For more detailed information on September soil moisture and evapotranspiration across Australia, access the Australian Landscape Water Balance site.

Climate influences

The tropical Pacific Ocean remains El Niño–Southern Oscillation neutral. Sea surface temperatures (SSTs) are currently cooler than average but within the neutral range. Other indicators, such as the Southern Oscillation Index (SOI) and trade winds, also remain at neutral levels.

All international climate models surveyed by the Bureau suggest further cooling of the tropical Pacific Ocean is likely. Five of the eight models suggest SSTs will cool to La Niña thresholds by December 2017, but only four maintain these levels for long enough to be classified as a La Niña.

The Indian Ocean Dipole (IOD) is currently neutral with most models suggesting neutral IOD is likely to continue. Three of the six climate models surveyed suggest positive IOD thresholds may be reached during spring, but it may now be too late to become an event. A positive IOD is typically associated with below-average winter–spring rainfall, and increased spring–summer fire potential over central and southern Australia.

Get the latest El Niño update in our fortnightly ENSO Wrap-Up. Find out about likely seasonal rainfall conditions in our current Rainfall outlook. For a range of other detailed information on Australia's climate go to Climate Information.

Service updates

The probability distribution graph has been replaced with a new boxplot. The boxplots provide an easier comparison between the probabilistic forecast and historical reference distributions.

7–day streamflow forecasting service

The Bureau now also delivers 7-day streamflow forecasts for more than 100 sites around Australia.

Combining near real-time rainfall and streamflow observations with rainfall forecasts, we calculate how much runoff is likely, and flow of this water down the stream network. A forecast is generated for each of the next seven days. Access the 7-day streamflow forecasts.


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