Scheduled Downtime
On Friday 21 April 2023 @ 5pm MT, this website will be down for maintenance and expected to return online the morning of 24 April 2023 at the latest


  1. S

    prec_acc_dt gives zero values

    Hi I'm trying to set the prec_acc_dt = 60 (mins) on my namelist but when I get the results prec_acc_c and prec_acc_nc variables are zero. I checked the accumulated rain values and RAINC is zero, RAINNC gives precipitation I cannot find the mistake on my namelist, could you help me? Thanks
  2. A

    Add EFFC variable to WRF-Chem output in morrison microphysics

    Hi all, I want to output EFFC (Cloud droplet effective radius) to the WRF-Chem output file. These are the steps I followed: 1. Added 'EFFC' in the MP_MORR_TWO_MOMENT subroutine in phys/module_mp_morr_two_moment.F file similar to rainprod/evapprod in line 575. 2. Added 'EFFC' in line 140 and...
  3. D

    Cloud sensitivity to CCN-INP using QNWFA_QNIFA_QNBCA_SIGMA_MONTHLY.dat file

    Hi all, I will be using the aerosol-aware Thompson scheme to look at the sensitivity of clouds to initial CCN and INP concentrations. I was wondering if I am supposed to change the content of the QNWFA_QNIFA_QNBCA_SIGMA_MONTHLY.dat file to do that. If not, I would appreciate your insights on...
  4. S

    WRF Ensemble technique

    I'm looking for an ensemble technique, and I remember using it in other numerical models and I think it was also used in WRF, but I'd like to know the specific method. This is a method of using the effects of multiple physics processes in one experiment. Once dynamics is performed, it then...
  5. I

    Cumulus: on or off for 5 km grid spacing?

    Hello everyone, I am interested in precipitation output from WRF. Currently I am defining my domains and I would like to ask if nested domains of 15km and 5km are a suitable choice for precipitation? Additionally, I am unsure if I need to activate the cumulus scheme for both domains, or only for...
  6. W

    Is RADT supposed to be the same for all domains?

    The variable radt is a little confusing in the namelist description above. So If I have a domain that is 9-3-1km should radt be set for 9 across all domains or 9-3-1 for each of it's domains?
  7. O

    Cold Input Sounding

    Hi everyone, I am trying to reproduce this Thompson paper, "Explicit Forecasts of Winter Precipitation Using an Improved Bulk Microphysics Scheme. Part II: Implementation of a New Snow Parameterization," using the Thompson microphysics. My challenge right now is finding the right input-sounding...
  8. L

    Problem with wind and the change of vertical layers.

    Hello everyone, Sorry for my English. You'll see, I've run WRF with the default distribution of vertical layers (in my case, e_vert=35). For a better resolution in the lower layers, I set up the following distribution: eta_levels = 1.000, 0.998, 0.994, 0.990, 0.988, 0.982...
  9. S

    P3 microphysics scheme modification

    I want to make some changes to the MP P3 scheme based on some literature review I see in the phys folder there are four files for this scheme: module_mp_p3.F module_mp_p3.f90 module_mp_p3.mod module_mp_p3.o I started modifying the module_mp_p3.F file and left the others untouched. After...
  10. Y

    Question about aerosol-aware thompson scheme with use_aero_icbc = .false.

    Hi all, I am running WRF model (version 4.2.2) using aerosol-aware thompson scheme (mp_physics=28) with use_aero_icbc = .false. In fact, I want to use this microphysics scheme in the context of a very low aerosol number concentration. Thus, I modify the naCCN0, naCCN1, naIN0 and naIN1 in...
  11. Y

    Question about aerosol-aware thompson scheme

    Hello all, I am currently using the aerosol-aware thompson scheme to do some simulation work. But I have some doubts. I want to compare the effect of aerosols on meteorological elements (such as precipitation and temperature, etc.), so I need to carry out two experiments, one with aerosols...
  12. X

    Calculation about h_diabatic in subroutine moist_physics_finish_em

    Dear Sir or Madam, I looked in the code of subroutine moist_physics_finish_em in module_big_step_utilities_em.F file. According to the code, moist theta is updated by summation of the following terms: pre-microphysics moist theta, theta tendency times (1+1.61*post-microphysics Qv) and 1.61...
  13. P

    Unusual tiling in precipitation field while using WRF aerosol-aware microphysics scheme

    I am seeing unusual tiling in the precipitation field simulated by WRF aerosol microphysics scheme of Song and Zhang, 2011, i.e., mp_physics = 40, which is used together with cu_physics = 11. I have 3 domains in my simulations and tiling is happening in all three domains. I am using WRF V4.4...
  14. M

    Hail in Fast-SBM

    Dear WRF Users! How can I activate hail in Fast-SBM microphysics parameterization? I can run my simulations with graupel, using the same parameterization with 33 bins input. In this case, the hail is 0 for all grid points. I read that the hail can be simulated with 43 bins, but I do not know...