Seasonal Streamflow Forecasts

Date: May–July 2018

  • Low streamflows likely for May to July
  • Low flows observed at over sixty percent of locations in April, with near-median and high flows dominating along the Queensland coast
  • Both the El Niño–Southern Oscillation and Indian Ocean Dipole remain neutral

Streamflow forecast for May–July

For May–July 2018, low and near-median streamflows are more likely at 64 and 37 locations, respectively across Australia. High flows are expected at 18 locations, mostly along the Queensland coast. For this time of year, 61% of locations have very low to low forecast skill, with most of the 17% of high skill locations occurring across northern Australia.

Forecasts have not been issued for 63 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

April catchment conditions

Low streamflows were recorded at 104 locations, mostly spread across southern Australia. Near-median and high flows were recorded at 54 and 13 locations, respectively. They were mostly in Queensland as water following heavy rain in March continues to work its way through the catchments.

Rainfall across Australia, as a whole, was two-thirds below average for April. The month was the driest April since 1997 and drier than average across all the states and territories. Only a few isolated patches across Australia received above-average rainfall for the month.

Below-average actual evapotranspiration (ET) for April in most of New South Wales, Victoria, South Australia, and areas in western and central Western Australia and western Northern Territory. The main areas of above-average ET were likely the result of water supplied from higher soil moisture, which included most of western and northern Queensland, eastern and northern Northern Territory, southeast Western Australia and most of Tasmania.

Modelled lower-layer soil moisture (10–100cm) was below average across most of the States and Territories. While above-average soil moisture occurred only in western and northern Queensland, eastern and northern parts of Northern Territory, southeast Western Australia and Tasmania—much of it remnant from high rainfall in recent months.

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

Climate influences

Most significant climate drivers of Australian rainfall and temperature patterns are neutral. The tropical Pacific Ocean is El Niño–Southern Oscillation neutral. Most models suggest this will continue through the southern hemisphere autumn and winter.

The Indian Ocean Dipole (IOD) is currently neutral. Half of the surveyed climate models suggest the IOD will remain neutral for winter, while the other half predict a negative IOD. However, the present above-average Sea Surface Temperatures (SST) off northwest Australia are a result of reduced cloud cover increasing solar warming. If this pattern persists, a typical negative IOD response, such as more cloud off northwest Australia, is less likely. During negative IOD events, winter-spring rainfall is typically above average over 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 also delivers 7-day streamflow forecasts for more than 160 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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