Message 10097
Available since version: 2026.2.0
Description
The water surface elevation at a 2D mesh cell has exceeded the upper stability limit set by Stability Limits ==. The water surface stability limit is the first argument of Stability Limits ==. TUFLOW FV checks solution bounds after applying initial conditions and periodically during the simulation.
Suggestions
The stability limits can be adjusted using the Stability Limits == command. The first argument is the upper bound for water surface elevation in mRL (or ftRL). Ensure it is set well above the maximum expected water level and topography/bathymetry values in the domain. Setting a water level stability limit lower than the maximum topographic/bathymetric Zb in the model domain is a common cause of this error.
The simulation time at which the error occurs may help to diagnose the issue. If the error occurs early in the simulation or at initialisation, it is likely a model configuration, initial condition or boundary condition mismatch. If the error occurs later during the simulation and the model configuration appears correct, the region surrounding the offending 2D cell warrants further investigation for instabilities.
If the error occurs at initialisation, check the initial condition data for water surface values that exceed the configured limit. The 2d cell ID in the message can be matched to a point in the GIS messages output file.
For model instability, review the model setup in the vicinity of the cell shown in the GIS messages output file. Common causes include a timestep that is too large for the mesh resolution, poor mesh quality near the affected cell and extreme or incorrectly specified boundary conditions.
While the error will be reported at the first cell that exceeds the specified stability limit the root case may originate from a different cell, typically close by. To track where instability begins it may be useful to add a secondary output block with high temporal resolution at a time just prior to when the error occurs. For example, if the model crashes at 02/12/2008 21:15:36:
Output == NetCDF
Suffix == CHK ! For checking
Output Parameters == h, v ! Water level, velocity
Start Output == 02/12/2008 21:15:00 ! Time close to the error occurrence
Final Output == 02/12/2008 21:17:00 ! Time immediately after the crash, mainly for safety so the model cannot continue writing high temporal resolution output AND FILL UP RESULT STORAGE. BE CAREFUL!!!!
Output Interval == 1 ! (s) High temporal resolution output to help track initial cell where instability starts and propagation
End OutputThis block writes water level and velocity at 1 second intervals (0 will use the model timestep if higher temporal resolution is required) in a narrow window around the error. Stepping through the output in time allows identification of the initial cell where instability begins and its propagation path.
The command Write Restart At Time == can also be useful to start a follow-up run close to the time of the error.