It is possible. Check this link:

http://www2.mmm.ucar.edu/wrf/OnLineTutorial/Class/graphics/arwpost.php

This is the key part:

"To output on either pressure or height levels, set interp_method=1, and specify the pressure/height levels in the namelist parameter interp_levels"

Use it to modify your namelist.ARWpost file, for example

&interp

! interp_method = 0, ! 0 is model levels, -1 is nice height levels, 1 is user specified pressure/height

interp_method = 1,

interp_levels = 20.00, 25.00, 50.00, 100.00, 150.00, 200.00, 250.00, 300.00, 350.00, 400.00, 450.00, 500.00, 550.0, 600.0, 650.0, 700.0, 750.0, 800.0, 850.0, 900.0, 950.0, 1000.0, 1500.0,

/

Don't forget that you are actually interpolating between the calculated sigma levels of your model!

is there any similar way for WRF-NMM Model?

Seems you can do this for WRF-NMM using UPP software

http://www.dtcenter.org/wrf-nmm/users/overview/upp_overview.php

but I've never used WRF-NMM outputs or UPP.

Thanks Hector.

I also use NCL function wrf_user_intrp_3d that Theodore mentioned and I have validated results with observation values which there is no problem at all.

Thanks all for your valuable suggestions, I will try to use NCL.

An advantage of NCL is the simple installation with YUM or SUDO commands on Linux. Also, you can install it manually but some libraries are necessary to complete the installation. Nevertheless, the ready scripts at the site of NCL are oriented on ARW. For NMM you have to make many changes or to make new scripts. Also,  NCL is very slow for too large data processing, but it is excellent to make plots, contours etc. Also, you can see  GRADS: http://www.iges.org/grads/

Thanks george,

 I have used WRF model to forecast weather and seasonal climate for 2 years. Not only do I use  NCL function wrf_user_intrp_3d but also use ARWpost to process heigh levles from model output (WRF_ARW) . It's okey. Download sample script  quickly from my website or refer to NCL's website by following the link below. 

http://meteo.edu.vn/~hanhnt/TOOLS/wrf_Heigh_3d.ncl 

or

http://www.ncl.ucar.edu/Applications/wrf.shtml

Hi,

    I have used ARWpost to extract wind data at required height using WRF-ARW output. After successful running ARWpost, I tried to plot wind speed at various heights using grads, i am getting same plot for all the levels. How can i resolve this issue. I attached the namelist files. if i removed extrapolation option, then i am getting entire grid is undefined for all the height levels.

Hi, Thanks for all your valuable suggestions. Finally, I succeded by using NCL. I got output in text format. Can anyone, let me know, how can i get this output in netcdf format. I attached my script also here.

Waiting for your reply,

wrfout is automatically in netcdf

It looks like WRF-ARW model does not work well at lower elevation (3-10m) and it shows 999 values at these elevation. Is there any way to extract wind speed at lower elevation?

I am also getting only missing values i.e 99999 when I try to interpolate temperature at 10m or rather below 100m, the model is not able to interpolate properly. I used NCL software to interpolate at different height levels.

does anyone have successfully tried interpolating wrf data at lower elevations?

There are default variables: U10,V10 and T2 in wrf output file. Check if you these variables are of any use to you.

Hi Malleswararao,

I think you can do this by defining "eta_levels" in your namelist. input "&domains" section. After you enter the "p_top_requested", which is basically the top height based on pressure, if you define the "eta_levels", you will get your outputs in those specific heights defined by the ete_levels.

Hope this helps.

From WRF output, you have elevation and pressure for each sigma level. If you stretched your vertical grid with dense-enough sigma levels near the surface you can interpolate any 3D parameter to your target height or pressure value. You can use a mass weighted procedure to interpolate between the layers including your target height/pressure.

You can use NCL or python for the 3d interpolation of any parameter. Interpolate u and v components of wind at a particular level and calculate the direction.

The link of the wrf-python is following for 3d interpolation:

https://wrf-python.readthedocs.io/en/latest/user_api/generated/wrf.vinterp.html#wrf.vinterp.

All the best.

Dear all,

Thank you for you suggestions.

I have wrfout file for a hall country but I have collected data from some meteo stations, would like to ask you how I can restrict my python script in order to get maps for each meteo site. My target is to compare measured data and those simulated using wrf model.

Thank you.

Dear Maryam Golbazi ,

Can you explain me how I can define eta levels values corresponding to 12m, 60m, 80m,...

Thank you.