Australia and South Pacific

Last modified by S2S_regionact on 2021/12/15 13:14

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ACCESS-S (Australian Community Climate and Earth-System Simulator – Seasonal) is the Bureau of Meteorology's climate modelling system used for outlooks on weekly through to seasonal timescales. The system comprises a coupled atmosphere-ocean model, a data assimilation system and a strategy for generating forecast ensembles. ACCESS-S is based on the UK Met Office's global coupled model seasonal forecast system GloSea5-GC2 (Global Seasonal forecast system version 5 using the Global Coupled model configuration 2; MacLachlan et al. 2015), but has enhancements to the ensemble generation strategy to make it appropriate for sub-seasonal forecasting, and a larger ensemble size. The GloSea5-GC2 system is made available to BoM through the Unified Model Partnership, of which BoM is a core partner. 

ACCESS-S1 has been running at the Bureau in operations since 2019. The new version ACCESS-S2 went live on 19 October 2021, replacing ACCESS-S1 in all operational services. ACCESS-S2 has a longer hindcast period of 1981-2018 and a new ocean data assimilation system developed in-house at BoM.

The BoM works with CSIRO, UKMO, universities and industry to investigate drivers of forecast skill, research the prediction of extreme events and develop useful forecast products for customers on subseasonal to seasonal timescales.

Information on regional workshops

Institutions/Projects in the region working on S2S

  • Forewarned is Forearmed (FWFA): This national project will deliver direct value to farmers by providing forecasts of extremes and equipping them with the information and tools to be forewarned and prepared. The project outputs aim to decrease the impacts of extreme climate events on farm, and on business profit. The Bureau, working with several research partners, will develop and deliver forecasts of the likelihood of climate extremes on multi-week and seasonal timescales — beyond the 7-day weather forecast. The products will be focused on heat, cold and rainfall extremes, for example, "What is the likelihood of having a decile 10 rainfall this spring?"; "What is the chance of having a heatwave in the week after next?"; "What is the chance that the upcoming month will be extremely hot?"; "What is the likelihood of having more heavy rainfall events than usual in the upcoming fortnight?". This will provide farmers with the first ever forecasts of climate extremes in the weeks to seasons ahead. More information:
  • Northern Australia Climate Program (NACP): NACP will deliver innovative research, development and extension outcomes to improve the capacity of the red meat industry to manage drought and climate risk across northern Australia. Drought is one of the biggest challenges graziers face and has a significant impact on agricultural output, productivity and on-farm income. One of the three sub-projects is focused on improving the basic science and operational skill of seasonal, sub-seasonal (multi-week) and multi-year climate forecasting systems of direct relevance to the northern Australia red meat industry. More information:
  • Seasonal prediction of marine heatwaves: This collaborative project between CSIRO and the Bureau of Meteorology seeks to develop an experimental seasonal marine heatwave (MHW) forecast product(s) for Australian waters, based on ACCESS-S, and conduct the underpinning research and verification required. These prototype MHW products would be based on ACCESS-S, supported by scientific publications and developed in collaboration with stakeholders. The expectation would be future inclusion into the existing operational seasonal ocean outlook service for Australia, expanding the current user base and adding value to the existing service. For more information, see here.
  • Climate and Oceans Support Program in the Pacific (COSPPac): The primary aim of COSPPac to enhance the capacity of Pacific Islands to manage and mitigate the impacts of climate variability and tidal events. We work with stakeholders in the Islands to build tools that can forecast and report on climate, tides and the ocean. Aa part of this project, multi-week tropical cyclone outlooks for the North and South Pacific, and multiweek rainfall, tmax and tmin outlooks (and verification) are regularly provided in National Meteorological Service bulletins for a large number of Pacific Island countries. Outlooks can be accessed here: 

Key regionally-relevant S2S research questions & activities being pursued in the region

  • How does ENSO modify the impact of the MJO on Australian rainfall and temperature?

  • Can flash droughts (i.e. rapidly developing drought over several weeks) be usefully predicted for Agricultural users?

  • To what extent can the MJO be blamed for sometimes poor monthly and seasonal forecasts?

  • Do S2S forecasts of indices that combine rain/wind/temperature/humidity (e.g. a cattle chill index) have more skill and usefulness?

  • How best to combine daily forecasts to produce marine heatwaves predictions at S2S timescales?

  • Investigating extension of coupled NWP forecasts into the sub-seasonal timescale


  • Benthuysen JA, Smith GA, Spillman CM, Steinberg CR (2021) Subseasonal prediction of the 2020 Great Barrier Reef and Coral Sea marine heatwave. Environmental Research Letters.
  • Camp J, Wheeler MC, Hendon HH, Gregory PA, Marshall MG, Tory KJ, Watkins AB, MacLachlan C and Kuleshov Y, 2018: Skilful multiweek tropical cyclone prediction in ACCESS‐S1 and the role of the MJO. Quarterly Journal of the Royal Meteorological Society
  • Cowan T, Stone R, Wheeler M, and Griffiths M, 2020: Improving the seasonal prediction of Northern Australian rainfall onset to help with grazing management decisions, Climate Services.
  • Cowan T, Wheeler M, Alves O, Narsey S, de Burgh-Day C, Griffiths M, Jarvis C, Cobon DH, Hawcroft MK, 2019: Forecasting the extreme rainfall, low temperatures, and strong winds associated with the northern Queensland floods of February 2019. Weather and Climate Extremes, 26, 100232.
  • de Burgh-Day C, Griffiths M, Yan H, Young G, Hudson D, Alves O, 2020: An adaptable framework for development and real time production of experimental sub-seasonal to seasonal forecast products, Bureau Research Report, No. 42. Bureau of Meteorology Australia.
  • deMott C, Muñoz AG, Roberts CD, Spillman CM, Vitart F (2021) Ocean Weather Forecasting in a Changing Climate. EOS.
  • Hendon HH, Lim E, Abhik S, 2020: Impact of interannual ozone variations on the downward coupling of the 2002 Southern Hemisphere stratospheric warming. Journal of Geophysical Research: Atmospheres, 125, e2020JD032952.
  • Hudson, D., Alves, O., Hendon, H.H., Lim, E., Liu, G., Luo J.-J., MacLachlan, C., Marshall, A.G., Shi, L., Wang, G., Wedd, R., Young, G., Zhao, M., Zhou X., 2017: ACCESS-S1: The new Bureau of Meteorology multi-week to seasonal prediction system. Journal of Southern Hemisphere Earth Systems Science, 67:3 132-159. 
  • King AD, Hudson D, Lim, E-P, Marshall AG, Hendon HH, Lane TP, Alves O. 2020: Sub-seasonal to seasonal prediction of rainfall extremes in Australia. Quarterly Journal of the Royal Meteorological Society, doi:10.1002/qj.3789. 
  • Lim, Y., Son, SW., Marshall, A.G. et al. 2019: Influence of the QBO on MJO prediction skill in the subseasonal-to-seasonal prediction models Climate Dynamics
  • Lim E, Hendon HH, Boschat G, Hudson D, Thompson DWJ, Dowdy A, Arblaster J, 2019: Australian hot and dry extremes induced by weakenings of the stratospheric polar vortex. Nature Geoscience 12, 896–901 (2019).
  • Lim E, Hendon HH and co-authors, 2021: The 2019 Southern Hemisphere polar stratospheric warming and its impacts. Submitted to the Bulletin of the American Meteorological Society,
  • Lim E, Hendon HH, Shi L, de Burgh-Day C, Hudson D, King A, Trewin B, Griffiths M and Marshall A, 2021: Tropical forcing of Australian extreme low minimum temperatures in September 2019. Climate Dynamics,
  • Lim E, Hudson DA, Wheeler M et al, 2021: Why Australia was Not Wet during Spring 2020 despite La Niña. Scientific Reports. 
  • Marshall AG and Hendon HH, 2019: Multi-week prediction of the Madden-Julian oscillation with ACCESS-S1. Climate Dynamics, pp.1-16.
  • Marshall AG, Hendon HH, de Burgh-Day and Griffiths M, 2021: Subseasonal drivers of extreme fire weather in Australia and its prediction in ACCESS-S1 during spring and summer. Climate Dynamics. doi:10.1007/s00382-021-05920-8
  • Marshall AG, Hendon HH, and Hudson D, 2021: Influence of the Madden-Julian Oscillation on multiweek prediction of Australian rainfall extremes using the ACCESS-S1 prediction system. Journal of Southern Hemisphere Earth Systems Science. 
  • Smith GA and Spillman CM, 2019: New high-resolution sea surface temperature forecasts for coral reef management on the Great Barrier Reef. Coral Reefs.
  • Spillman CM and Smith GA, 2021: A new operational seasonal thermal stress prediction tool for coral reefs around Australia. Frontiers of Marine Science. doi:10.3389/fmars.2021.687833
  • Spillman CM, Smith GA, Hobday AJ, Hartog JR (2021) Onset and decline rates of marine heatwaves: global trends, seasonal forecasts and marine management. Frontiers of Marine Science, accepted.
  • Wang G and Hendon HH, 2020: Impacts of the Madden–Julian Oscillation on wintertime Australian minimum temperatures and Southern Hemisphere circulation. Climate Dynamics.

Created by Administrator on 2021/04/27 14:11
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