Seasonal sea level forecasts for the Australian Coastline
Subseasonal to seasonal variations in coastal water levels, associated with climate drivers such as the El Niño-Southern Oscillation and other weekly to monthly scale atmospheric and oceanographic processes, contribute to coastal sea level extremes by raising the baseline sea level on top of which storm surges and tides act. Along with astronomical tides these subseasonal to seasonal variations are potentially predictable weeks to months in advance, information that could be used to construct an early warning system for coastal flooding hazards. With this aim in mind, we present a forecast skill assessment of the Bureau of Meteorology’s seasonal prediction system, ACCESS-S2, for sea level around the Australian coastline at seasonal time scales between 1 and 7 months. ACCESS-S2 has seasonal skill on the North and West Coasts, where anomalies associated with tropical climate drivers and coastal trapped waves can reach up to 20 cm. Inclusion of the inverse barometer impact on sea level as a post-processing step increases skill in most regions due to ACCESS-S2’s ability to forecast atmospheric pressure variations. Please come along to discuss next steps, including the additional ingredients needed to construct a future probabilistic early warning system for Australian coastal flooding hazards.
Note: this topic is part of the 2023 ACCESS Community Workshop Poster session