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setting for max_dom and parent_grid_ratio

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Dear Colleagues,

I use WRF 3.8.1, and would like to know the max number of domains(max_dom has no limit? what is the most common setting for it?), as well as the max parent_grid_ratio(1:5:5?) among the coarsest domain to its nested domains.

Looking forward to hearing from soon.

Best wishes,
Hi Stella,
I apologize that your original question was overlooked. We recommend using no more than about 5 max total domains. At some point, the number of processors you would need for a very high-resolution (large grid number) domain would be much greater than the number you would be allowed to use for the coarse/small outer domains. As for parent_grid_ratio, we recommend using odd numbers, and typically only advise to use either a 5:1 or 3:1 ratio.

You may find this document useful for any additional questions you have.