Hello everyone,
I am trying to run WRF v4.5.2 with four nested domains (27 km, 9 km, 3 km and 1 km) for an 8-day simulation (20–28 July 2022) using ERA5 boundary conditions.
With my original configuration (outer-domain time_step = 45 s), the model consistently stops at approximately the same model time (2022-07-20 08:54), regardless of whether I use 16, 24 or 32 MPI processes. In all cases, the model terminates in the microphysics routine with the following message:
** STOPPING IN MICROPHYSICS: (Part 2, end) **<br>** i,k,T [K]: 20 24 -381.133240<br>
I then started reducing the outer-domain timestep. A single-domain (27 km) simulation eventually completed successfully for the entire period (20–28 July 2022), but only after reducing the outer-domain timestep to 15 s. I am currently testing the three nested domains configuration with the same timestep, and so far it has progressed well beyond the previous crash point.
What surprises me is that a 15 s timestep seems extremely small for a 27 km outer domain. Most recommendations suggest much larger values (e.g. around 6 × dx), so I suspect there may be another underlying issue rather than the timestep itself.
My model uses WRF v4.5.2 with four nested domains (27/9/3/1 km) and 196 vertical levels.
I have attached my namelist.input, rsl.out.0000, rsl.out.0021 (where the microphysics error occurs), and rsl.error.0021.
Has anyone encountered a similar problem or has any suggestions on what might be causing the need for such a small timestep? Are there any diagnostics or namelist options that you would recommend checking?
Thank you very much for any suggestions.
I am trying to run WRF v4.5.2 with four nested domains (27 km, 9 km, 3 km and 1 km) for an 8-day simulation (20–28 July 2022) using ERA5 boundary conditions.
With my original configuration (outer-domain time_step = 45 s), the model consistently stops at approximately the same model time (2022-07-20 08:54), regardless of whether I use 16, 24 or 32 MPI processes. In all cases, the model terminates in the microphysics routine with the following message:
** STOPPING IN MICROPHYSICS: (Part 2, end) **<br>** i,k,T [K]: 20 24 -381.133240<br>
I then started reducing the outer-domain timestep. A single-domain (27 km) simulation eventually completed successfully for the entire period (20–28 July 2022), but only after reducing the outer-domain timestep to 15 s. I am currently testing the three nested domains configuration with the same timestep, and so far it has progressed well beyond the previous crash point.
What surprises me is that a 15 s timestep seems extremely small for a 27 km outer domain. Most recommendations suggest much larger values (e.g. around 6 × dx), so I suspect there may be another underlying issue rather than the timestep itself.
My model uses WRF v4.5.2 with four nested domains (27/9/3/1 km) and 196 vertical levels.
I have attached my namelist.input, rsl.out.0000, rsl.out.0021 (where the microphysics error occurs), and rsl.error.0021.
Has anyone encountered a similar problem or has any suggestions on what might be causing the need for such a small timestep? Are there any diagnostics or namelist options that you would recommend checking?
Thank you very much for any suggestions.