ERA5 Forecast Field Data

Topics related to running the ungrib.exe program
Post Reply
xkcd_xkcd
Posts: 18
Joined: Fri Nov 13, 2020 2:51 am

ERA5 Forecast Field Data

Post by xkcd_xkcd » Mon Jan 04, 2021 3:29 am

Hi,
I want to do a forecast with ERA5 data. So I download ERA5 reanalysis data (https://cds.climate.copernicus.eu/cdsap ... b=overview) as initial condition and forecast data (https://apps.ecmwf.int/data-catalogues/era5/?class=ea) as boundary forcing condition.
An error occurred when I run ungrib.exe.
./ungrib.exe
*** Starting program ungrib.exe ***
Start_date = 2019-01-01_00:00:00 , End_date = 2019-01-02_00:00:00
output format is WPS
Path to intermediate files is ./
Unknown Data Representation Type, ksec2(4)= 50
rd_grib1
Who can help me with this? Thanks very much in advance!

Kind regards!
Peng

kwerner
Posts: 2287
Joined: Wed Feb 14, 2018 9:21 pm

Re: ERA5 Forecast Field Data

Post by kwerner » Thu Jan 07, 2021 5:14 pm

Hi,
Just to make sure you're downloading the correct data, take a look at this FAQ that discusses using ERA5 data.

Are you able to use the g1print.exe or g2print.exe utility on the data to read it?
If you're still having problems, can you attach one time stamp of your data files so that I can test it, along with your namelist.wps file?
Please also let me know the version of WPS you are using, and which Vtable. Thanks!
NCAR/MMM

xkcd_xkcd
Posts: 18
Joined: Fri Nov 13, 2020 2:51 am

Re: ERA5 Forecast Field Data

Post by xkcd_xkcd » Mon Jan 11, 2021 1:30 pm

Hi,
Thanks very much for your reply!
I have run the WRF Model with ERA5 reanalysis data (from 2019-01-01-0000 to 2019-01-02-0000) successfully following the tutorial from https://dreambooker.site/2019/10/03/Ini ... ure-level/, I think this is a simulation case.

But what I want is a WRF forecast case. So I downloaded the reanalysis 2019-01-01-0000 data as the initial condition, and I downloaded the forecast field data as the boundary forcing condition, which starts from 2019-01-01-0600 and forecasts to 2019-01-02-0000 every hour. Then the error occurred after executing ungrib.exe. (All the data I downloaded is based on the tutorial)

What confuses me is that I can succeed with ERA5 reanalysis data but not with forecast field data.

I have run a 3.7.1 version WRF, the vtable is Vtable.ERA-interim.pl and the namelist.wps is as follows.

Kind regards!
Peng
Attachments
namelist.wps
(1.46 KiB) Downloaded 16 times

kwerner
Posts: 2287
Joined: Wed Feb 14, 2018 9:21 pm

Re: ERA5 Forecast Field Data

Post by kwerner » Fri Jan 15, 2021 5:25 pm

Hi,
Can you try to use the Vtable.ECMWF to ungrib this data and see if it makes any difference? Please keep me posted. Thanks!
NCAR/MMM

milancurcic
Posts: 13
Joined: Mon Aug 03, 2020 4:31 pm

Re: ERA5 Forecast Field Data

Post by milancurcic » Fri Jan 15, 2021 6:10 pm

Hi Kelly, I couldn't post in the ERA5 FAQ (viewtopic.php?f=75&t=9714) so I'm posting in this thread:

For the attached file name in that post, the correct line to add to namelist.wps is:

Code: Select all

constants_name = 'ERA5_INVARIANT.txt'

xkcd_xkcd
Posts: 18
Joined: Fri Nov 13, 2020 2:51 am

Re: ERA5 Forecast Field Data

Post by xkcd_xkcd » Sat Jan 16, 2021 4:10 am

hi,
I have tried with Vtable.ECMWF and the same error occurred.
I think this error may be due to the difference between the reanalysis data and forecast data of ERA5. Because I can run WRF successfully with reanalysis data. But I don't know the reason.
I wonder is there anyone who has run WRF with ERA5 forecast data as boundary forcing condition.

Kind regards.
Peng

kwerner
Posts: 2287
Joined: Wed Feb 14, 2018 9:21 pm

Re: ERA5 Forecast Field Data

Post by kwerner » Tue Jan 19, 2021 7:49 pm

Peng,
Thanks for letting me know about the update to the FAQ for ERA5 data. I made some modifications.

I asked our data specialist, who hasn't used the ERA5 forecast data, but thinks the format should be the same as the analysis data; however, maybe that's not the case. Can you attach one time stamp of your data files so that I can test it? Thanks!
NCAR/MMM

xkcd_xkcd
Posts: 18
Joined: Fri Nov 13, 2020 2:51 am

Re: ERA5 Forecast Field Data

Post by xkcd_xkcd » Wed Jan 20, 2021 2:45 am

Hi,

Thank you very much for your reply.

Initial data is the ERA5 reanalysis data of 2019-01-01-0600 including pressure level and single level. Boundary forcing data is the ERA5 forecast data of 2019-01-01-0600 to 2019-01-01-1200 including pressure level and single level.

The attachments provide namelist.wps and the variables I have downloaded including both reanalysis data and forecast data. And the URL of the data is in the previous forum reply.

Hope my reply is clear. Looking forward to your reply.
Kind regards.
Peng
Attachments
namelist.wps
(1.49 KiB) Downloaded 12 times
pressure_level.png
singel_level.png

kwerner
Posts: 2287
Joined: Wed Feb 14, 2018 9:21 pm

Re: ERA5 Forecast Field Data

Post by kwerner » Wed Jan 20, 2021 1:00 pm

Hi,
Is it not possible for you to simply attach the input files (you can package multiple files in a single .tar file)? It will take me much more time to follow the website you sent, choosing each individual field, level, time, etc. and our resources are limited for time. I also want to ensure I'm using the EXACT data files as you, to repeat the problem. If I download the files, there's a decent chance I'll do something differently than you. If the file(s) are too large, take a look at the home page of this forum for information on attaching large files. Thanks.
NCAR/MMM

xkcd_xkcd
Posts: 18
Joined: Fri Nov 13, 2020 2:51 am

Re: ERA5 Forecast Field Data

Post by xkcd_xkcd » Mon Feb 01, 2021 8:01 am

Hi,

Thank you very much for your patient reply.

I have uploaded the data file named ERA5_input_example_xkcd.tar to this website.https://nextcloud.mmm.ucar.edu/nextclou ... N3nHMQr1Ov
Hope it works.

Best regards.

kwerner
Posts: 2287
Joined: Wed Feb 14, 2018 9:21 pm

Re: ERA5 Forecast Field Data

Post by kwerner » Mon Feb 08, 2021 11:04 pm

Hi,
Thank you so much for sending that, and I would like to apologize for the delay. I was out of the office last week and am trying to get caught up now. Thank you for your patience.

I am seeing the same error as you. The difference I see in your reanalysis data, and in the forecast data is that the forecast data includes several forecast times within a single file. The WPS program sometimes has problems with multiple times in a file. As a test, is it possible to just download a single forecast time and see if that would work, or whether you get the same error?
NCAR/MMM

xkcd_xkcd
Posts: 18
Joined: Fri Nov 13, 2020 2:51 am

Re: ERA5 Forecast Field Data

Post by xkcd_xkcd » Tue Feb 16, 2021 4:43 am

Hi,

Thank you very much for your reply.
I have tried but unfortunately, the same error occurred.
I will post again if I solve this problem in the future.
Thanks again and best wishes.

Peng

kwerner
Posts: 2287
Joined: Wed Feb 14, 2018 9:21 pm

Re: ERA5 Forecast Field Data

Post by kwerner » Wed Feb 17, 2021 5:24 pm

Peng,
Yes, please keep us posted. As we've not worked with the forecast data previously, it would be nice to know what the trick is to making this work, if you get it working. We could share it with future users with the same problem.
NCAR/MMM

Post Reply

Return to “ungrib”