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Cannot run the WRF V4.0 with WRF 3.9 input with the use_theta_m=1 option

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Dear Colleges,

I am running the WRF v4.0 model with the wrfinput files obtained from the previous WRF V with the use_theta_m =1 option.
I am not able to run the WRF v4.0 with use_theta_m =1 option, because the wrf.exe complains that:

---- ERROR: Cannot have old input data when requesting use_theta_m=1

So, I have to set use_theta_m =0 (which shows poorer results) to run the wrf.exe (v4.0).
Please note, I have already set force_use_old_data = .true. in my namelist.input file (attached).

Best regards,


  • namelist.txt
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Hi Artur,
That is correct. Unfortunately if you want to use the 'use_theta_m = 1' option, you cannot use input that is prior to V4.0, and if you want to use that older input, you must set 'use_theta_m = 0.' It is mentioned in this chapter of our Users' Guide:

Dear Kelly,

That is sad to know. The reason I have to use the wrfinput from the WRF V 3.9.1 is that WRFDA V4.0 does not assimilate radar data properly (it seems there is a bug). I have already reported on that:

So, I have to use WRFDA 3.9.1 for radar data assimilation. Then, the problem occurs when running the wrf.exe (WRF v4.0).

Hopefully, the problem will be solved soon with the WRFDA V4.0, and I can use the WRF V4.0.

Best regards,