Abstract 009

Abstract ID: 009

Predicting ocean extremes at subseasonal to seasonal timescales for operational decision support

Lead Author: Claire Spillman
BoM, Australia

Keywords: seasonal prediction, marine management, marine heatwave, climate variability, ACCESS-S

Abstract: Extreme ocean events, including marine heatwaves and high sea level events, have implications for many marine systems, industries and coastal communities. Subseasonal to seasonal forecasting has an important role to play in both predicting and understanding these extreme ocean events and providing advance warning for risk mitigation and operational decision support.

Operational sea surface temperature and thermal stress outlooks from 2 weeks to 6 months into the future have been publicly provided for Australian waters by the Bureau of Meteorology since 2018. These outlooks are used by a wide range of stakeholders including marine management agencies, fisheries and Defence. Building on this service to provide greater impact and value to marine users, experimental seasonal marine heatwave forecast products are currently in development. These forecasts can provide a ‘preparation window’ for marine stakeholders to implement proactive management strategies prior to a marine heatwave. Similarly, advance warning of extreme high coastal water levels on subseasonal to seasonal timescales can inform strategic and operational responses to reduce the impacts of these events. Work is underway to develop an operational seasonal sealevel service to provide coastal sealevel forecasts beyond a weather forecast (1-7 days) out to several months into the future for the Australian region. Future forecast products would combine seasonal forecast information with tidal predictions and global sealevel rise estimates.

Advance warning of high-risk conditions allows for proactive management responses and helps maintain industry profitability in an uncertain environment. Forecasts can provide a ‘preparation window’ for marine stakeholders to implement proactive management strategies prior to an event, noting however that not all industries have the same level of agility to respond. Subseasonal to seasonal forecast tools, that are useful, usable and used, will be valuable tools to assist marine stakeholders in managing climate risk and vulnerability in a warming climate.

Grant Smith (Bureau of Meteorology, Australia)
Alistair Hobday (CSIRO Environment, Australia)
Jason Hartog (CSIRO Environment, Australia)