# Mpas-jedi B sample data's date

**URL:** <https://forums.jcsda.org/t/mpas-jedi-b-sample-datas-date/724>\
**Category:** JEDI\
**Created:** [February 26, 2026, 12:47pm UTC](https://forums.jcsda.org/t/mpas-jedi-b-sample-datas-date/724 "2026-02-26T12:47:49Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![rqin\_624](https://yyz1.discourse-cdn.com/flex031/user_avatar/forums.jcsda.org/rqin_624/32/274_2.png) [@rqin\_624](https://forums.jcsda.org/u/rqin_624)\
**Post date:** [February 26, 2026, 12:47pm UTC](https://forums.jcsda.org/t/mpas-jedi-b-sample-datas-date/724/1 "2026-02-26T12:47:49Z")

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Hi, I have a question about the mpas-jedi B sample data’s date.

in 3\_convert\_uv\_to\_psichi.bash:

![image](https://yyz1.discourse-cdn.com/flex031/images/transparent.png)

the commented “# f\_fcst=…” line, is a more common dir structure “init\_dir/output.valid\_date.nc“.

but the actually used “f\_fcst=…” line, is a dir structure “valid\_dir/init.valid\_date.nc”.

then ncdump -c, or ncdmp -v xtime, to see the actual used file,

find it’s truely a “init file” with the “right\_to\_be\_used valid date”,

not a “forecast valid file“, from a “init dir” with lead “24h” or “48h” to the “mpasout.valid\_date.nc”, like the “# f\_fcst=…” line’s dir and file structure.

so, how are these sample\_data generated? and is that ok to use the dir\_file\_structure like the “# f\_fcst=…” line indicated?

thanks.

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**Author:** ![discourse\_ai\_spam](https://avatars.discourse-cdn.com/v4/letter/d/c68b51/32.png) [@discourse\_ai\_spam](https://forums.jcsda.org/u/discourse_ai_spam)\
**Post date:** [February 26, 2026, 4:30pm UTC](https://forums.jcsda.org/t/mpas-jedi-b-sample-datas-date/724/2 "2026-02-26T16:30:56Z")

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**Author:** ![system](https://canada1.discourse-cdn.com/flex031/uploads/jcsda/original/1X/8792155b899a50973ee3f11b55354eac17c7785a.gif) [@system](https://forums.jcsda.org/u/system)\
**Post date:** [February 28, 2026, 2:37pm UTC](https://forums.jcsda.org/t/mpas-jedi-b-sample-datas-date/724/3 "2026-02-28T14:37:09Z")

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**Author:** ![byoung-joo](https://yyz1.discourse-cdn.com/flex031/user_avatar/forums.jcsda.org/byoung-joo/32/126_2.png) [@byoung-joo](https://forums.jcsda.org/u/byoung-joo)\
**Post date:** [March 6, 2026, 5:35pm UTC](https://forums.jcsda.org/t/mpas-jedi-b-sample-datas-date/724/4 "2026-03-06T17:35:04Z")

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Hi @rqin_624,

For this samples, MPAS initial files are initialized with the GRIB files of either GFS 24 hour forecast or GFS 48 hour forecast.

If you want to use MPAS’s own forecast samples, you can refer the structure of " “# f\_fcst=…”.

Hope this helps,

BJ