# Formatting NEXRAD for WRFDA

**URL:** <https://openradar.discourse.group/t/formatting-nexrad-for-wrfda/578>\
**Category:** General\
**Created:** [March 20, 2025, 9:11pm UTC](https://openradar.discourse.group/t/formatting-nexrad-for-wrfda/578 "2025-03-20T21:11:31Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![ebercosh](https://avatars.discourse-cdn.com/v4/letter/e/90db22/32.png) [@ebercosh](https://openradar.discourse.group/u/ebercosh)\
**Post date:** [March 20, 2025, 9:11pm UTC](https://openradar.discourse.group/t/formatting-nexrad-for-wrfda/578/1 "2025-03-20T21:11:31Z")

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Hello,

I am attempting to use NEXRAD level 2 data with the Weather Research and Forecasting (WRF) model data assimilation program (WRFDA). From my understanding, in order for WRFDA to read in the radar data, it needs to be in a specific format shown on slide 18 “Example of data format” shown [here](https://www2.mmm.ucar.edu/wrf/users/wrfda/Tutorials/2015_Aug/docs/WRFDA_Radar.pdf). I have been using Py-Art to read in a single NEXRAD level 2 file, but I am not quite sure how to properly parse the data into the WRF format. For example, the WRFDA format needs a total number of soundings, and then each sounding has a specific block of text associated with it. In the NEXRAD file, I see sweeps, rays, and gates, and am not sure how to appropriately map this to the sounding information in the WRFDA format.

Thanks in advance!  
Emily

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**Author:** ![mgrover1](https://yyz2.discourse-cdn.com/free1/user_avatar/openradar.discourse.group/mgrover1/32/7_2.png) [@mgrover1](https://openradar.discourse.group/u/mgrover1)\
**Post date:** [March 25, 2025, 3:43pm UTC](https://openradar.discourse.group/t/formatting-nexrad-for-wrfda/578/2 "2025-03-25T15:43:48Z")

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I do not know of any examples of doing this - I would encourage you to reach out to data assimilation groups within NOAA?

If you are interested in extracting columns within the radar data, you could use a feature in Py-ART [Extract a radar column above a point — Py-ART 2.0.1 documentation](https://arm-doe.github.io/pyart/examples/retrieve/plot_column_subset.html)

This seems like a workflow that would require a fair amount of work - open to other suggestions! But I am unfamiliar of any folks who have done this.

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**Author:** ![syedhamidali](https://yyz2.discourse-cdn.com/free1/user_avatar/openradar.discourse.group/syedhamidali/32/377_2.png) [@syedhamidali](https://openradar.discourse.group/u/syedhamidali)\
**Post date:** [March 25, 2025, 10:30pm UTC](https://openradar.discourse.group/t/formatting-nexrad-for-wrfda/578/3 "2025-03-25T22:30:06Z")

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I was able to accomplish this using the KNMI [ERA-URBAN/fm128\_radar\_knmi](https://github.com/ERA-URBAN/fm128_radar_knmi/tree/master) package, though it required older Wradlib functions. I tested it on their dataset, and replicating that format for other data would require significant effort.

You can check out my example on [GitHub](https://github.com/syedhamidali/test_scripts/blob/syedhamidali-patch-1/WRFDA_Assimilation_KNMI_FM-128.ipynb). If I manage to adapt it for NEXRAD data, I’ll post it here. I also tried to write a function (which you can find [here](https://github.com/syedhamidali/test_scripts/blob/syedhamidali-patch-1/wrfada_nexrad_to_fm-128.ipynb), though it is still incomplete) to convert the radar data into fm-128 format, and then you can simply use [ERA-URBAN/fm128\_radar](https://github.com/ERA-URBAN/fm128_radar) package to get the WRFDA ascii format.

🔗 [GitHub Link](https://github.com/syedhamidali/test_scripts/blob/syedhamidali-patch-1/WRFDA_Assimilation_KNMI_FM-128.ipynb)

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**Author:** ![mgrover1](https://yyz2.discourse-cdn.com/free1/user_avatar/openradar.discourse.group/mgrover1/32/7_2.png) [@mgrover1](https://openradar.discourse.group/u/mgrover1)\
**Post date:** [March 26, 2025, 2:44pm UTC](https://openradar.discourse.group/t/formatting-nexrad-for-wrfda/578/4 "2025-03-26T14:44:08Z")

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Thanks for sharing this!!
