[Met_help] [rt.rap.ucar.edu #61523] History for Using pcp_combine to created files for Mode tool

John Halley Gotway via RT met_help at ucar.edu
Fri May 24 11:24:47 MDT 2013


----------------------------------------------------------------
  Initial Request
----------------------------------------------------------------

Hello,

I am attempting to create precip accumulation files for input into the MET
mode tool using the pcp_combine tool. I am taking two GRIB files and
subtracting one from the other, but when I run pcp_combine thusly:

pcp_combine \
-subtract \
/nfs4/mi_tmdl/WRFGRB/wrfout_d02_2005-01-01_12:00:00.grb 12 \
/nfs4/mi_tmdl/WRFGRB/wrfout_d02_2005-01-01_06:00:00.grb 6 \
/data/wrf/wrf_mode/wrf_pcp_d02_2005_01_01_12_6hr

I get this error:

ERROR: get_field() -> can't find grib code 61 with accumulation of 120000
in GRIB file: /nfs4/mi_tmdl/WRFGRB/wrfout_d02_2005-01-01_12:00:00.grb

However, when I use the wgrib command to look at
/.../wrfout_d03_2005-01-01_12:00:00.gb, I find this information:

278:19207484:d=04123100:APCP:kpds5=61:kpds6=1:kpds7=0:TR=4:P1=0:P2=36:TimeU=1:sfc:0-36hr
acc:NAve=0

Since the variable is APCP, or accumulated precip, I take this to be the
pertinent grib code. Am I missing some syntax, or am I doing something
wrong to run this tool?

Thank you for your help,

-- 
Zachary Ebenstein
University of Michigan
College of Engineering
Dept. Atmospheric, Oceanic and Space Sciences
Climate Physics (B.S.E), Dec. 2011


----------------------------------------------------------------
  Complete Ticket History
----------------------------------------------------------------

Subject: Re: [rt.rap.ucar.edu #61523] Using pcp_combine to created files for Mode tool
From: John Halley Gotway
Time: Thu May 23 14:55:56 2013

Zac,

I see that you're using pcp_combine to perform a subtraction command
in order to compute a 6-hour accumulation of precipitation.

Running wgrib on the input files to see what they contain is a great
thing to do!  And reading the wgrib output you sent, I see that that
file contains a 0-36 hour accumulation.  See the "0-36hr acc"
in the wgrib output:
    278:19207484:d=04123100:APCP:kpds5=61:kpds6=1:kpds7=0:TR=4:P1=0:P2=36:TimeU=1:sfc:0-
36hr acc:NAve=0

However, when you run pcp_combine, you're asking it to find a 12-hour
accumulation.  It errors out because that file contains a 36-hour
accumulation, not 12-hours.  I suspect the following command
will do what you want:

pcp_combine \
-subtract \
/nfs4/mi_tmdl/WRFGRB/wrfout_d02_2005-01-01_12:00:00.grb 36 \
/nfs4/mi_tmdl/WRFGRB/wrfout_d02_2005-01-01_06:00:00.grb 30 \
/data/wrf/wrf_mode/wrf_pcp_d02_2005_01_01_12_6hr

I'm guessing the confusion here is coming from the naming convention
of the wrfout files.  They contain the valid time stamp in their names
- not the forecast lead time.  You probably saw that the
files were valid at 12:00:00 and 06:00:00 and assumed they were from
the initialization at 00Z that day.  But they must have been from the
previous day's initialization since they contain 36 and
30-hour accumulations.

Make sense?

Thanks,
John Halley Gotway
met_help at ucar.edu

On 05/23/2013 11:04 AM, Zachary Ebenstein via RT wrote:
>
> Thu May 23 11:04:56 2013: Request 61523 was acted upon.
> Transaction: Ticket created by ebenszac at umich.edu
>         Queue: met_help
>       Subject: Using pcp_combine to created files for Mode tool
>         Owner: Nobody
>    Requestors: ebenszac at umich.edu
>        Status: new
>   Ticket <URL:
https://rt.rap.ucar.edu/rt/Ticket/Display.html?id=61523 >
>
>
> Hello,
>
> I am attempting to create precip accumulation files for input into
the MET
> mode tool using the pcp_combine tool. I am taking two GRIB files and
> subtracting one from the other, but when I run pcp_combine thusly:
>
> pcp_combine \
> -subtract \
> /nfs4/mi_tmdl/WRFGRB/wrfout_d02_2005-01-01_12:00:00.grb 12 \
> /nfs4/mi_tmdl/WRFGRB/wrfout_d02_2005-01-01_06:00:00.grb 6 \
> /data/wrf/wrf_mode/wrf_pcp_d02_2005_01_01_12_6hr
>
> I get this error:
>
> ERROR: get_field() -> can't find grib code 61 with accumulation of
120000
> in GRIB file: /nfs4/mi_tmdl/WRFGRB/wrfout_d02_2005-01-
01_12:00:00.grb
>
> However, when I use the wgrib command to look at
> /.../wrfout_d03_2005-01-01_12:00:00.gb, I find this information:
>
>
278:19207484:d=04123100:APCP:kpds5=61:kpds6=1:kpds7=0:TR=4:P1=0:P2=36:TimeU=1:sfc:0-
36hr
> acc:NAve=0
>
> Since the variable is APCP, or accumulated precip, I take this to be
the
> pertinent grib code. Am I missing some syntax, or am I doing
something
> wrong to run this tool?
>
> Thank you for your help,
>

------------------------------------------------
Subject: Using pcp_combine to created files for Mode tool
From: Zachary Ebenstein
Time: Fri May 24 11:23:24 2013

Thank you, that suggestion worked perfectly! I was misinterpreting the
accumulation in the GRIB files as having accumulations up to 36 hrs
inclusive.

Thanks,

Zac


On Thu, May 23, 2013 at 4:55 PM, John Halley Gotway via RT <
met_help at ucar.edu> wrote:

> Zac,
>
> I see that you're using pcp_combine to perform a subtraction command
in
> order to compute a 6-hour accumulation of precipitation.
>
> Running wgrib on the input files to see what they contain is a great
thing
> to do!  And reading the wgrib output you sent, I see that that file
> contains a 0-36 hour accumulation.  See the "0-36hr acc"
> in the wgrib output:
>
>
278:19207484:d=04123100:APCP:kpds5=61:kpds6=1:kpds7=0:TR=4:P1=0:P2=36:TimeU=1:sfc:0-
36hr
> acc:NAve=0
>
> However, when you run pcp_combine, you're asking it to find a 12-
hour
> accumulation.  It errors out because that file contains a 36-hour
> accumulation, not 12-hours.  I suspect the following command
> will do what you want:
>
> pcp_combine \
> -subtract \
> /nfs4/mi_tmdl/WRFGRB/wrfout_d02_2005-01-01_12:00:00.grb 36 \
> /nfs4/mi_tmdl/WRFGRB/wrfout_d02_2005-01-01_06:00:00.grb 30 \
> /data/wrf/wrf_mode/wrf_pcp_d02_2005_01_01_12_6hr
>
> I'm guessing the confusion here is coming from the naming convention
of
> the wrfout files.  They contain the valid time stamp in their names
- not
> the forecast lead time.  You probably saw that the
> files were valid at 12:00:00 and 06:00:00 and assumed they were from
the
> initialization at 00Z that day.  But they must have been from the
previous
> day's initialization since they contain 36 and
> 30-hour accumulations.
>
> Make sense?
>
> Thanks,
> John Halley Gotway
> met_help at ucar.edu
>
> On 05/23/2013 11:04 AM, Zachary Ebenstein via RT wrote:
> >
> > Thu May 23 11:04:56 2013: Request 61523 was acted upon.
> > Transaction: Ticket created by ebenszac at umich.edu
> >         Queue: met_help
> >       Subject: Using pcp_combine to created files for Mode tool
> >         Owner: Nobody
> >    Requestors: ebenszac at umich.edu
> >        Status: new
> >   Ticket <URL:
https://rt.rap.ucar.edu/rt/Ticket/Display.html?id=61523 >
> >
> >
> > Hello,
> >
> > I am attempting to create precip accumulation files for input into
the
> MET
> > mode tool using the pcp_combine tool. I am taking two GRIB files
and
> > subtracting one from the other, but when I run pcp_combine thusly:
> >
> > pcp_combine \
> > -subtract \
> > /nfs4/mi_tmdl/WRFGRB/wrfout_d02_2005-01-01_12:00:00.grb 12 \
> > /nfs4/mi_tmdl/WRFGRB/wrfout_d02_2005-01-01_06:00:00.grb 6 \
> > /data/wrf/wrf_mode/wrf_pcp_d02_2005_01_01_12_6hr
> >
> > I get this error:
> >
> > ERROR: get_field() -> can't find grib code 61 with accumulation of
120000
> > in GRIB file: /nfs4/mi_tmdl/WRFGRB/wrfout_d02_2005-01-
01_12:00:00.grb
> >
> > However, when I use the wgrib command to look at
> > /.../wrfout_d03_2005-01-01_12:00:00.gb, I find this information:
> >
> >
>
278:19207484:d=04123100:APCP:kpds5=61:kpds6=1:kpds7=0:TR=4:P1=0:P2=36:TimeU=1:sfc:0-
36hr
> > acc:NAve=0
> >
> > Since the variable is APCP, or accumulated precip, I take this to
be the
> > pertinent grib code. Am I missing some syntax, or am I doing
something
> > wrong to run this tool?
> >
> > Thank you for your help,
> >
>
>


--
Zachary Ebenstein
University of Michigan
College of Engineering
Dept. Atmospheric, Oceanic and Space Sciences
Climate Physics (B.S.E), Dec. 2011

------------------------------------------------
Subject: Re: [rt.rap.ucar.edu #61523] Using pcp_combine to created files for Mode tool
From: John Halley Gotway
Time: Fri May 24 11:24:20 2013

Zac,

Great, glad you were able to get that working.

Thanks,
John

On 05/24/2013 11:23 AM, Zachary Ebenstein via RT wrote:
>
> <URL: https://rt.rap.ucar.edu/rt/Ticket/Display.html?id=61523 >
>
> Thank you, that suggestion worked perfectly! I was misinterpreting
the
> accumulation in the GRIB files as having accumulations up to 36 hrs
> inclusive.
>
> Thanks,
>
> Zac
>
>
> On Thu, May 23, 2013 at 4:55 PM, John Halley Gotway via RT <
> met_help at ucar.edu> wrote:
>
>> Zac,
>>
>> I see that you're using pcp_combine to perform a subtraction
command in
>> order to compute a 6-hour accumulation of precipitation.
>>
>> Running wgrib on the input files to see what they contain is a
great thing
>> to do!  And reading the wgrib output you sent, I see that that file
>> contains a 0-36 hour accumulation.  See the "0-36hr acc"
>> in the wgrib output:
>>
>>
278:19207484:d=04123100:APCP:kpds5=61:kpds6=1:kpds7=0:TR=4:P1=0:P2=36:TimeU=1:sfc:0-
36hr
>> acc:NAve=0
>>
>> However, when you run pcp_combine, you're asking it to find a 12-
hour
>> accumulation.  It errors out because that file contains a 36-hour
>> accumulation, not 12-hours.  I suspect the following command
>> will do what you want:
>>
>> pcp_combine \
>> -subtract \
>> /nfs4/mi_tmdl/WRFGRB/wrfout_d02_2005-01-01_12:00:00.grb 36 \
>> /nfs4/mi_tmdl/WRFGRB/wrfout_d02_2005-01-01_06:00:00.grb 30 \
>> /data/wrf/wrf_mode/wrf_pcp_d02_2005_01_01_12_6hr
>>
>> I'm guessing the confusion here is coming from the naming
convention of
>> the wrfout files.  They contain the valid time stamp in their names
- not
>> the forecast lead time.  You probably saw that the
>> files were valid at 12:00:00 and 06:00:00 and assumed they were
from the
>> initialization at 00Z that day.  But they must have been from the
previous
>> day's initialization since they contain 36 and
>> 30-hour accumulations.
>>
>> Make sense?
>>
>> Thanks,
>> John Halley Gotway
>> met_help at ucar.edu
>>
>> On 05/23/2013 11:04 AM, Zachary Ebenstein via RT wrote:
>>>
>>> Thu May 23 11:04:56 2013: Request 61523 was acted upon.
>>> Transaction: Ticket created by ebenszac at umich.edu
>>>          Queue: met_help
>>>        Subject: Using pcp_combine to created files for Mode tool
>>>          Owner: Nobody
>>>     Requestors: ebenszac at umich.edu
>>>         Status: new
>>>    Ticket <URL:
https://rt.rap.ucar.edu/rt/Ticket/Display.html?id=61523 >
>>>
>>>
>>> Hello,
>>>
>>> I am attempting to create precip accumulation files for input into
the
>> MET
>>> mode tool using the pcp_combine tool. I am taking two GRIB files
and
>>> subtracting one from the other, but when I run pcp_combine thusly:
>>>
>>> pcp_combine \
>>> -subtract \
>>> /nfs4/mi_tmdl/WRFGRB/wrfout_d02_2005-01-01_12:00:00.grb 12 \
>>> /nfs4/mi_tmdl/WRFGRB/wrfout_d02_2005-01-01_06:00:00.grb 6 \
>>> /data/wrf/wrf_mode/wrf_pcp_d02_2005_01_01_12_6hr
>>>
>>> I get this error:
>>>
>>> ERROR: get_field() -> can't find grib code 61 with accumulation of
120000
>>> in GRIB file: /nfs4/mi_tmdl/WRFGRB/wrfout_d02_2005-01-
01_12:00:00.grb
>>>
>>> However, when I use the wgrib command to look at
>>> /.../wrfout_d03_2005-01-01_12:00:00.gb, I find this information:
>>>
>>>
>>
278:19207484:d=04123100:APCP:kpds5=61:kpds6=1:kpds7=0:TR=4:P1=0:P2=36:TimeU=1:sfc:0-
36hr
>>> acc:NAve=0
>>>
>>> Since the variable is APCP, or accumulated precip, I take this to
be the
>>> pertinent grib code. Am I missing some syntax, or am I doing
something
>>> wrong to run this tool?
>>>
>>> Thank you for your help,
>>>
>>
>>
>
>

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