Message 10092

TUFLOW FV

Available since version: 2026.2.0

ERROR 10092 - Timestep has gone negative, possibly due to a negative cell dZ

Description

This error is raised when the CFL-based adaptive timestep calculation produces a negative value, possibly due to a negative cell layer thickness (dZ).

Suggestions

Review the model near the GIS message location for unusual velocities or flow behaviour leading up to the error. Review the mesh quality in the region near the error. Review the model timestepping in the log file and CFL diagnostic output csv files for any evidence of other cells with low minimum or average timesteps.

To track where instability begins, add a secondary output block with high temporal resolution at a time just prior to the error. See ERROR 10097 for an example output block.