This website contains trial products from the Seasonal Outlooks for Coastal High Tide Flooding (SOHTF) coastal sea level forecasts system.

The SOHTF forecast system combines forecasts for several different components of coastal sea level variability at tide gauges:

• Harmonic tide predictions (based on the UTide tidal software)
• Sea level rise estimates (based on a polynomial extrapolation of past data)
• Climatological information on storm surges (based on past statistics at this location)
• Subseasonal-to-seasonal coastal sea level forecasts from the Bureau of Meteorologies seasonal forecast system, ACCESS-S2.

SOHTF uses this information to construct:

• Probabilistic forecasts for daily maximum and minimum sea level from 2 weeks to 12 months into the future.
• The daily probability of exceeding pre-defined flooding thresholds.

Further information can be found via these links.

• SOHTF fact sheet and poster presentation.
• Holmes et al. (2025), Seasonal outlooks for coastal high tide flooding. Scientific research paper published in Natural Hazards. JOURNAL LINK, PDF LINK
• Holmes et al. (2025), Seasonal sea level forecasts for the Australian coast. Scientific research paper published in the Journal of Southern Hemisphere Earth System Science. JOURNAL LINK, PDF LINK

Static plots can be viewed at the following

SOHTF Forecast Visualisation Tool

An interactive SOHTF web app is available at

SOHTF Forecast Interactive Tool

These tools contain two types of trial output products from SOHTF:

• SOHTF calendars: These calendars display SOHTF output in calendar form for the next 12 months, including flooding risk (threshold exceedance probability for a range of thresholds), predicted high and low tides and tidal range.
• SOHTF time series: These time series display the daily maximum sea level at the given tide gauge (top panel) and the probability that this sea level exceeds a certain threshold (bottom panel).

These pages are password protected. For login details please contact Seasonal High Tide Flooding .

The products are EXPERIMENTAL ONLY and do NOT currently form part of the Bureau's standard services in any way. Access to the products is made available for trial purposes only and on the basis that users are fully aware that these products are being tested and that users will not issue these products as real-time forecasts in any way. The forecast products are subject to the Bureau's copyright and disclaimer.

The following conditions apply:

• Products are not official Bureau products, they are prototype products
• Products are only to be used for trial purposes to assess their usefulness and not as an ongoing service
• Products are not operationally supported, they may occasionally be unavailable for periods of up to 2 weeks e.g., due to system upgrades
• The look and feel of products may change at any stage without notice
• Products may be added and removed at any stage without notice