Seasonal Streamflow Forecasts

Date: August–October 2017

  • Near-median and low streamflows likely to dominate for August to October
  • Low flows observed at more than 60% of locations in July
  • El Niño–Southern Oscillation and Indian Ocean Dipole are currently neutral

Streamflow forecast for August–October

For August–October 2017, near-median and low streamflows are more likely at 71 and 56 locations across Australia, respectively. High flows are expected at 32 locations. More than three-quarters of locations have moderate to high forecast skill for this time of year, which are fairly evenly scattered around mainland Australia. Forecasts have not been issued for 22 locations due to very low model skill or missing observed data. We suggest using the observed climatology for these locations.

Forecasts for locations in the southeast, in particular, have been influenced by a large month-on-month increase in the Southern Oscillation Index (SOI) value. As a result, more near-median streamflows are forecast where low flows were indicated in last month's forecast.

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

July catchment conditions

Low streamflows were recorded at 110 locations, mostly across the eastern states and southern Australia, including Tasmania. Near-median and high flows were recorded at 40 and 19 locations respectively, mainly in the northern half of the country.

The Australian total rainfall for July was just below two-thirds of the average. Nearly all states received below-average rainfall, with New South Wales receiving less than one-third of its average, and both South Australia and Western Australia receiving half of their respective averages. Northern Territory was the only exception with more than double its average rainfall.

Actual evapotranspiration (ET) was average for most of Australia, with large areas of below-average ET over most of New South Wales and parts of southern and western Western Australia that are roughly coincident with drier soils. There are smaller patches of above-average ET over western Victoria, northeastern Tasmania, central Northern Territory, northern Queensland, coastal northern New South Wales and the southwestern tip of Western Australia—areas where there was either average to above-average rainfall or average to above-average soil moisture providing a water source. Above-average rainfall also led to increases in the modelled lower–layer soil moisture (10–100cm) for the southwestern tip of Western Australia and central Northern Territory.

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

Climate influences

The El Niño–Southern Oscillation (ENSO) remains neutral—neither El Niño nor La Niña. All international models surveyed by the Bureau indicate the tropical Pacific Ocean should remain ENSO-neutral for the rest of 2017.

The Indian Ocean Dipole (IOD) is also neutral, with two of six international climate models indicating positive IOD thresholds could be reached in the next few months. Though only one predicts conditions will persist for long enough for a positive IOD to eventuate.

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.

In this release we have added six new locations in the Northern Territory and fourteen in Queensland.

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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