arw2arl: Output time interval not constant

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aragong
Posts: 8
Joined: November 13th, 2020, 9:08 am
Registered HYSPLIT User: Yes
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arw2arl: Output time interval not constant

Post by aragong »

Hi everybody!

I am trying to convert the WRF standard output from a Spanish data provider (http://mandeo.meteogalicia.es/thredds/c ... g_raw.html) to hysplit format and the following error appears:

Code: Select all

./arw2arl -i../../files/wrfout_d01_20210204_0000.nc -oARL.BIN
 Using an existing decoding configuration: WRFDATA.CFG
 Output time interval not constant
 Initial delta (min):    60.0000000
Looking at the nc-file using Panoply seems like everything is ok and the DT is 60min but this is my very first time using this converter and I am not sure if I am running a bad configuration of the converter. My WRFDATA.CFG reads as:

Code: Select all

&SETUP
 num3dv = 7,
 arw3dv = 'P','T','U','V','W','X','QVAPOR',
 cnv3dv =  0.01, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0,
 arl3dv = 'PRES','TEMP','UWND','VWND','WWND','DIFW','SPHU',
 num2dv = 12,
 arw2dv = 'HGT','PSFC','RAIN','X','PBLH','UST','SWDOWN','HFX','LH','T2','U10','V10',
 cnv2dv = 1.0, 0.01, 0.001, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0,
 arl2dv = 'SHGT','PRSS','TPP1','DIFR','PBLH','USTR ','DSWF','SHTF','LHTF','T02M','U10M','V10M',
/
As far as I know... I am not using any other configuration file. The provider is OpenAccess for downloading in the link above, so I do not attach netcdf details... tell me if anyone wants me to post them here.
Please, could you help me to solve this provider conversion in other to feed my Hysplit models??

Thank you in advance for your time!
best regards,
Fantine
Posts: 118
Joined: November 8th, 2012, 3:41 pm

Re: arw2arl: Output time interval not constant

Post by Fantine »

I downloaded the file (wrfout_d01_20210207_0000.nc) from the website and ran the converter (arw2arl) successfully using the WRFDATA.CFG attached to your post.
The error message you got came from checking the "XTIME" variable in the WRF file. You can add "-d" option when running arw2arl that will give you a diagnostic printout. Please check if the download of the WRF file was complete and the file contains all hourly data.
aragong
Posts: 8
Joined: November 13th, 2020, 9:08 am
Registered HYSPLIT User: Yes
Contact:

Re: arw2arl: Output time interval not constant

Post by aragong »

You are totally right!

The nc file was incomplete. I was able to download the last forecast using wget in linux terminal and the conversion works fine!

Sorry about the waste of time and thank you very much for checking my error and reply to the post!

Best regards,
ankitpatel0698
Posts: 1
Joined: March 17th, 2021, 12:14 pm
Registered HYSPLIT User: No

Re: arw2arl: Output time interval not constant

Post by ankitpatel0698 »

I run WRF model and trying to convert wrfout (nc format) to ARL. But i am getting the same error as discussed above. NEED URGENT HELP.
AS FOLLOWS in linux:
./arw2arl -i/home/ankit/403/WRF-4.0.3/run/wrfout_d01_2020-01-02_00\:00\:00 -c2
Using an existing decoding configuration: WRFDATA.CFG
Output time interval not constant
Initial delta (min): 61.8661652
Delta at period: 59.1763306 3

#Then tried using -d in the command line.

./arw2arl -i/home/ankit/403/WRF-4.0.3/run/wrfout_d01_2020-01-02_00\:00\:00 -d -c2
Using an existing decoding configuration: WRFDATA.CFG
Opened NetCDF input file on unit: 65536
Time = 1
Number of times = 25
DateStrLen = 2
Date String Length = 19
west_east = 3
Number of x points = 99
south_north = 4
Number of y points = 74
bottom_top = 5
Number of z points = 33
NetCDF file contains 25 time periods
Times = 1
Number of dimensions = 2
Dimension IDs = 2 1
Length = 19
Length = 25
2020-01-02_00:00:00
2020-01-02_01:01:51
2020-01-02_02:01:02
2020-01-02_03:00:13
2020-01-02_04:02:05
2020-01-02_05:01:15
2020-01-02_06:00:26
2020-01-02_07:02:18
2020-01-02_08:01:28
2020-01-02_09:00:39
2020-01-02_10:02:31
2020-01-02_11:01:41
2020-01-02_12:00:52
2020-01-02_13:00:03
2020-01-02_14:01:55
2020-01-02_15:01:05
2020-01-02_16:00:16
2020-01-02_17:02:08
2020-01-02_18:01:18
2020-01-02_19:00:29
2020-01-02_20:02:21
2020-01-02_21:01:31
2020-01-02_22:00:42
2020-01-02_23:02:34
2020-01-03_00:01:45
XTIME = 58
Number of dimensions = 1
Dimension IDs = 1
Length = 25
0.00000000
61.8661652
121.042496
180.218826
242.084991
301.261322
360.437653
422.303833
481.480164
540.656494
602.522644
661.699036
720.875305
780.051636
841.917847
901.094116
960.270508
1022.13672
1081.31299
1140.48926
1202.35547
1261.53186
1320.70813
1382.57434
1441.75061
0.00000000 2020-01-02_00:00:00
61.8661652 2020-01-02_01:01:51
121.042496 2020-01-02_02:01:02
Output time interval not constant
Initial delta (min): 61.8661652
Delta at period: 59.1763306 3
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christopher.loughner
Posts: 35
Joined: August 15th, 2017, 3:59 pm
Registered HYSPLIT User: No

Re: arw2arl: Output time interval not constant

Post by christopher.loughner »

You need to make sure WRF is output at a constant interval. You need to edit your WRF namelist.input file to ensure that your output time step is divisible by your model time step. If you are using the adaptive time step, you need to ensure that the output is being written out at the desired output time. Please consult the WRF user guide.
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