Seasonal Streamflow Forecasts

Date: January–March 2018

  • Near-median streamflows more likely for January to March 2018
  • Low and near-median flows observed at more than two-thirds of locations in December 2017
  • La Niña persists in the tropical Pacific

Streamflow forecast for January–March

For January–March 2018, near-median flows are more likely at 55 locations scattered across Australia. Low flows are expected at 39 locations, mostly in the south. High flows are expected at 36 locations, also mostly in southern Australia. High forecast skill (51 locations) is confined to southern Australia, while moderate (40 locations) and low (46 locations) forecast skill are scattered around the country.

Forecasts have not been issued for 50 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

December 2017 catchment conditions

Low December 2017 streamflows were recorded at 66 locations, scattered around Australia. Near-median flows were recorded at 60 locations, also scattered across the country. While high flows were at 47 locations, mostly in the south including southeast Queensland.

December 2017 rainfall was below-average for most of Queensland and the Northern Territory. There were also scattered patches of below-average rainfall across other parts of the country, most notably in Western Australia and north South Australia. Rainfall was mostly average to above-average across the rest of Australia.

Actual evapotranspiration (ET) was above-average for most of South Australia, Victoria, and southern and central New South Wales—areas where there was mostly average to high rainfall and generally wetter soils for the month. There were also areas of above-average ET in southeast coastal Queensland, in the south of Northern Territory and the top end, and also parts of the north and east of Western Australia. The rest of the country had mostly average ET for December, with below-average ET occurring through western Tasmania and mostly in scattered patches around Western Australia, and central and western Queensland.

Modelled lower-layer soil moisture (10–100cm) was above-average across northern and interior parts of Western Australia through to South Australia, Victoria and the southern half of New South Wales due to high December rainfall. Areas in Northern Territory were also above-average, where moisture persisted from high November rainfall. The rest of the country had mostly average to below-average soil moisture.

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

Climate influences

Pacific Ocean climate patterns indicate a weak La Niña persists in the tropical Pacific. The event is expected to be short-lived, and end in the southern autumn of 2018.

Both the latest sea surface temperatures in the central to eastern tropical Pacific, and cloud patterns in the atmosphere, remain typical of a La Niña. However, warming water beneath the surface of the western Pacific may be a precursor to the end of this event in the coming months. For 2017-18 to be classed as a La Niña year, thresholds need to be exceeded for at least three months. Most climate models surveyed by the Bureau suggest this event is likely to last through the southern summer up to early autumn of 2018.

La Niña typically brings above-average rainfall to eastern Australia during summer. However, with a weak event expected, there should be a reduced influence on Australian rainfall. La Niña events can also increase the likelihood of prolonged warm spells for southeastern Australia.

The Indian Ocean Dipole (IOD) is currently neutral. IOD events are unable to form between December and April.

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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