[Met_help] [rt.rap.ucar.edu #78833] History for pcp_combine with sub-hourly accumulations
John Halley Gotway via RT
met_help at ucar.edu
Thu Dec 22 10:19:27 MST 2016
----------------------------------------------------------------
Initial Request
----------------------------------------------------------------
Hello,
I am trying to run a simple test of pcp_combine and mode, using sub-hourly grib files output from WRF UPP as the inputs to pcp_combine. The scripts and input files are attached, although the input grib files are just soft links and the output of wgrib -v are in forecast.grb.contents and forecast2.grb.contents in order to keep the file size small. Can you please tell me what is wrong with the command in test_pcpcombine.sh?
Thanks,
Aaron
----------------------------------------------------------------
Complete Ticket History
----------------------------------------------------------------
Subject: pcp_combine with sub-hourly accumulations
From: John Halley Gotway
Time: Wed Dec 07 10:07:19 2016
Hello Aaron,
I see you're having trouble running pcp_combine with sub-hourly
accumulation intervals. Here's the command you're running:
pcp_combine -subtract forecast.grb 0055 forecast2.grb 0005
forecast.nc
-field APCP
I assume that you intend "0055" to mean 0 hours and 55 minutes and
"0005"
to mean 0 hours and 5 minutes.
Looking at the usage statement for pcp_combine (just type pcp_combine
with
no arguments), you'll see:
"accum1" indicates the accumulation interval to be used from
in_file1 in
HH[MMSS] format (required).
The time format listed "HH[MMSS]" means that you either specify hours
or
hours/minutes/seconds. You're currently using hours/minutes, and I
suspect
that's the problem.
Please try adding the seconds to the end of the time strings, like
this:
pcp_combine -subtract forecast.grb 005500 forecast2.grb 000500
forecast.nc -field APCP
Just let us know what other issues or questions you have in your use
of MET.
Thanks,
John Halley Gotway
On Tue, Dec 6, 2016 at 3:09 PM, Johnson, Aaron via RT
<met_help at ucar.edu>
wrote:
>
> Tue Dec 06 15:09:15 2016: Request 78833 was acted upon.
> Transaction: Ticket created by ajohns14 at ou.edu
> Queue: met_help
> Subject: pcp_combine with sub-hourly accumulations
> Owner: Nobody
> Requestors: ajohns14 at ou.edu
> Status: new
> Ticket <URL:
https://rt.rap.ucar.edu/rt/Ticket/Display.html?id=78833 >
>
>
> Hello,
>
> I am trying to run a simple test of pcp_combine and mode, using sub-
hourly
> grib files output from WRF UPP as the inputs to pcp_combine. The
scripts
> and input files are attached, although the input grib files are just
soft
> links and the output of wgrib -v are in forecast.grb.contents and
> forecast2.grb.contents in order to keep the file size small. Can
you
> please tell me what is wrong with the command in test_pcpcombine.sh?
>
> Thanks,
>
> Aaron
>
>
------------------------------------------------
Subject: pcp_combine with sub-hourly accumulations
From: Johnson, Aaron
Time: Wed Dec 07 10:48:31 2016
Hi John,
Thanks for the response. I also tried it the way you suggested and
got a similar error. I will copy the original error message, followed
by the new error message with that change, below. Is there something
else that I might be doing wrong?
Thanks,
Aaron
[ajohns at yslogin1 modetest]$ ./test_pcpcombine.sh
DEBUG 1: Reading input file: forecast.grb
ERROR :
ERROR : yyerror() -> syntax error in file "config_23175_0_.temp"
ERROR :
ERROR : line = 1
ERROR :
ERROR : column = 1
ERROR :
ERROR : text = "0055"
ERROR :
ERROR :
ERROR : 0055
ERROR : ^^^^
ERROR :
[ajohns at yslogin1 modetest]$ emacs test_pcpcombine.sh
[ajohns at yslogin1 modetest]$ ./test_pcpcombine.sh
DEBUG 1: Reading input file: forecast.grb
ERROR :
ERROR : yyerror() -> syntax error in file "config_26525_0_.temp"
ERROR :
ERROR : line = 2
ERROR :
ERROR : column = 1
ERROR :
ERROR : text = "(nul)"
ERROR :
ERROR :
ERROR : (nul)
ERROR : (nul)
ERROR :
[ajohns at yslogin1 modetest]$
________________________________
From: John Halley Gotway via RT <met_help at ucar.edu>
Sent: Wednesday, December 7, 2016 11:07:19 AM
To: Johnson, Aaron
Subject: Re: [rt.rap.ucar.edu #78833] pcp_combine with sub-hourly
accumulations
Hello Aaron,
I see you're having trouble running pcp_combine with sub-hourly
accumulation intervals. Here's the command you're running:
pcp_combine -subtract forecast.grb 0055 forecast2.grb 0005
forecast.nc
-field APCP
I assume that you intend "0055" to mean 0 hours and 55 minutes and
"0005"
to mean 0 hours and 5 minutes.
Looking at the usage statement for pcp_combine (just type pcp_combine
with
no arguments), you'll see:
"accum1" indicates the accumulation interval to be used from
in_file1 in
HH[MMSS] format (required).
The time format listed "HH[MMSS]" means that you either specify hours
or
hours/minutes/seconds. You're currently using hours/minutes, and I
suspect
that's the problem.
Please try adding the seconds to the end of the time strings, like
this:
pcp_combine -subtract forecast.grb 005500 forecast2.grb 000500
forecast.nc -field APCP
Just let us know what other issues or questions you have in your use
of MET.
Thanks,
John Halley Gotway
On Tue, Dec 6, 2016 at 3:09 PM, Johnson, Aaron via RT
<met_help at ucar.edu>
wrote:
>
> Tue Dec 06 15:09:15 2016: Request 78833 was acted upon.
> Transaction: Ticket created by ajohns14 at ou.edu
> Queue: met_help
> Subject: pcp_combine with sub-hourly accumulations
> Owner: Nobody
> Requestors: ajohns14 at ou.edu
> Status: new
> Ticket <URL:
https://rt.rap.ucar.edu/rt/Ticket/Display.html?id=78833 >
>
>
> Hello,
>
> I am trying to run a simple test of pcp_combine and mode, using sub-
hourly
> grib files output from WRF UPP as the inputs to pcp_combine. The
scripts
> and input files are attached, although the input grib files are just
soft
> links and the output of wgrib -v are in forecast.grb.contents and
> forecast2.grb.contents in order to keep the file size small. Can
you
> please tell me what is wrong with the command in test_pcpcombine.sh?
>
> Thanks,
>
> Aaron
>
>
------------------------------------------------
Subject: pcp_combine with sub-hourly accumulations
From: John Halley Gotway
Time: Wed Dec 07 10:56:15 2016
Aaron,
Any chance you could send me those grib files for testing?
You could post them to our anonymous ftp site, following these
instructions:
http://www.dtcenter.org/met/users/support/met_help.php#ftp
Thanks,
John
On Wed, Dec 7, 2016 at 10:48 AM, Johnson, Aaron via RT
<met_help at ucar.edu>
wrote:
>
> <URL: https://rt.rap.ucar.edu/rt/Ticket/Display.html?id=78833 >
>
> Hi John,
>
> Thanks for the response. I also tried it the way you suggested and
got a
> similar error. I will copy the original error message, followed by
the new
> error message with that change, below. Is there something else that
I
> might be doing wrong?
>
> Thanks,
>
> Aaron
>
>
>
> [ajohns at yslogin1 modetest]$ ./test_pcpcombine.sh
>
> DEBUG 1: Reading input file: forecast.grb
>
> ERROR :
>
> ERROR : yyerror() -> syntax error in file "config_23175_0_.temp"
>
> ERROR :
>
> ERROR : line = 1
>
> ERROR :
>
> ERROR : column = 1
>
> ERROR :
>
> ERROR : text = "0055"
>
> ERROR :
>
> ERROR :
>
> ERROR : 0055
>
> ERROR : ^^^^
>
> ERROR :
>
> [ajohns at yslogin1 modetest]$ emacs test_pcpcombine.sh
>
> [ajohns at yslogin1 modetest]$ ./test_pcpcombine.sh
>
> DEBUG 1: Reading input file: forecast.grb
>
> ERROR :
>
> ERROR : yyerror() -> syntax error in file "config_26525_0_.temp"
>
> ERROR :
>
> ERROR : line = 2
>
> ERROR :
>
> ERROR : column = 1
>
> ERROR :
>
> ERROR : text = "(nul)"
>
> ERROR :
>
> ERROR :
>
> ERROR : (nul)
>
> ERROR : (nul)
>
> ERROR :
>
> [ajohns at yslogin1 modetest]$
>
> ________________________________
> From: John Halley Gotway via RT <met_help at ucar.edu>
> Sent: Wednesday, December 7, 2016 11:07:19 AM
> To: Johnson, Aaron
> Subject: Re: [rt.rap.ucar.edu #78833] pcp_combine with sub-hourly
> accumulations
>
> Hello Aaron,
>
> I see you're having trouble running pcp_combine with sub-hourly
> accumulation intervals. Here's the command you're running:
> pcp_combine -subtract forecast.grb 0055 forecast2.grb 0005
forecast.nc
> -field APCP
>
> I assume that you intend "0055" to mean 0 hours and 55 minutes and
"0005"
> to mean 0 hours and 5 minutes.
>
> Looking at the usage statement for pcp_combine (just type
pcp_combine with
> no arguments), you'll see:
> "accum1" indicates the accumulation interval to be used from
in_file1 in
> HH[MMSS] format (required).
>
> The time format listed "HH[MMSS]" means that you either specify
hours or
> hours/minutes/seconds. You're currently using hours/minutes, and I
suspect
> that's the problem.
> Please try adding the seconds to the end of the time strings, like
this:
> pcp_combine -subtract forecast.grb 005500 forecast2.grb 000500
> forecast.nc -field APCP
>
> Just let us know what other issues or questions you have in your use
of
> MET.
>
> Thanks,
> John Halley Gotway
>
> On Tue, Dec 6, 2016 at 3:09 PM, Johnson, Aaron via RT
<met_help at ucar.edu>
> wrote:
>
> >
> > Tue Dec 06 15:09:15 2016: Request 78833 was acted upon.
> > Transaction: Ticket created by ajohns14 at ou.edu
> > Queue: met_help
> > Subject: pcp_combine with sub-hourly accumulations
> > Owner: Nobody
> > Requestors: ajohns14 at ou.edu
> > Status: new
> > Ticket <URL:
https://rt.rap.ucar.edu/rt/Ticket/Display.html?id=78833 >
> >
> >
> > Hello,
> >
> > I am trying to run a simple test of pcp_combine and mode, using
> sub-hourly
> > grib files output from WRF UPP as the inputs to pcp_combine. The
scripts
> > and input files are attached, although the input grib files are
just soft
> > links and the output of wgrib -v are in forecast.grb.contents and
> > forecast2.grb.contents in order to keep the file size small. Can
you
> > please tell me what is wrong with the command in
test_pcpcombine.sh?
> >
> > Thanks,
> >
> > Aaron
> >
> >
>
>
>
------------------------------------------------
Subject: pcp_combine with sub-hourly accumulations
From: Johnson, Aaron
Time: Wed Dec 07 11:06:05 2016
John,
I copied them incoming/irap/met_help/johnson_data/. Let me know if I
can provide any more information.
Thanks,
Aaron
________________________________
From: John Halley Gotway via RT <met_help at ucar.edu>
Sent: Wednesday, December 7, 2016 11:56:16 AM
To: Johnson, Aaron
Subject: Re: [rt.rap.ucar.edu #78833] pcp_combine with sub-hourly
accumulations
Aaron,
Any chance you could send me those grib files for testing?
You could post them to our anonymous ftp site, following these
instructions:
http://www.dtcenter.org/met/users/support/met_help.php#ftp
Thanks,
John
On Wed, Dec 7, 2016 at 10:48 AM, Johnson, Aaron via RT
<met_help at ucar.edu>
wrote:
>
> <URL: https://rt.rap.ucar.edu/rt/Ticket/Display.html?id=78833 >
>
> Hi John,
>
> Thanks for the response. I also tried it the way you suggested and
got a
> similar error. I will copy the original error message, followed by
the new
> error message with that change, below. Is there something else that
I
> might be doing wrong?
>
> Thanks,
>
> Aaron
>
>
>
> [ajohns at yslogin1 modetest]$ ./test_pcpcombine.sh
>
> DEBUG 1: Reading input file: forecast.grb
>
> ERROR :
>
> ERROR : yyerror() -> syntax error in file "config_23175_0_.temp"
>
> ERROR :
>
> ERROR : line = 1
>
> ERROR :
>
> ERROR : column = 1
>
> ERROR :
>
> ERROR : text = "0055"
>
> ERROR :
>
> ERROR :
>
> ERROR : 0055
>
> ERROR : ^^^^
>
> ERROR :
>
> [ajohns at yslogin1 modetest]$ emacs test_pcpcombine.sh
>
> [ajohns at yslogin1 modetest]$ ./test_pcpcombine.sh
>
> DEBUG 1: Reading input file: forecast.grb
>
> ERROR :
>
> ERROR : yyerror() -> syntax error in file "config_26525_0_.temp"
>
> ERROR :
>
> ERROR : line = 2
>
> ERROR :
>
> ERROR : column = 1
>
> ERROR :
>
> ERROR : text = "(nul)"
>
> ERROR :
>
> ERROR :
>
> ERROR : (nul)
>
> ERROR : (nul)
>
> ERROR :
>
> [ajohns at yslogin1 modetest]$
>
> ________________________________
> From: John Halley Gotway via RT <met_help at ucar.edu>
> Sent: Wednesday, December 7, 2016 11:07:19 AM
> To: Johnson, Aaron
> Subject: Re: [rt.rap.ucar.edu #78833] pcp_combine with sub-hourly
> accumulations
>
> Hello Aaron,
>
> I see you're having trouble running pcp_combine with sub-hourly
> accumulation intervals. Here's the command you're running:
> pcp_combine -subtract forecast.grb 0055 forecast2.grb 0005
forecast.nc
> -field APCP
>
> I assume that you intend "0055" to mean 0 hours and 55 minutes and
"0005"
> to mean 0 hours and 5 minutes.
>
> Looking at the usage statement for pcp_combine (just type
pcp_combine with
> no arguments), you'll see:
> "accum1" indicates the accumulation interval to be used from
in_file1 in
> HH[MMSS] format (required).
>
> The time format listed "HH[MMSS]" means that you either specify
hours or
> hours/minutes/seconds. You're currently using hours/minutes, and I
suspect
> that's the problem.
> Please try adding the seconds to the end of the time strings, like
this:
> pcp_combine -subtract forecast.grb 005500 forecast2.grb 000500
> forecast.nc -field APCP
>
> Just let us know what other issues or questions you have in your use
of
> MET.
>
> Thanks,
> John Halley Gotway
>
> On Tue, Dec 6, 2016 at 3:09 PM, Johnson, Aaron via RT
<met_help at ucar.edu>
> wrote:
>
> >
> > Tue Dec 06 15:09:15 2016: Request 78833 was acted upon.
> > Transaction: Ticket created by ajohns14 at ou.edu
> > Queue: met_help
> > Subject: pcp_combine with sub-hourly accumulations
> > Owner: Nobody
> > Requestors: ajohns14 at ou.edu
> > Status: new
> > Ticket <URL:
https://rt.rap.ucar.edu/rt/Ticket/Display.html?id=78833 >
> >
> >
> > Hello,
> >
> > I am trying to run a simple test of pcp_combine and mode, using
> sub-hourly
> > grib files output from WRF UPP as the inputs to pcp_combine. The
scripts
> > and input files are attached, although the input grib files are
just soft
> > links and the output of wgrib -v are in forecast.grb.contents and
> > forecast2.grb.contents in order to keep the file size small. Can
you
> > please tell me what is wrong with the command in
test_pcpcombine.sh?
> >
> > Thanks,
> >
> > Aaron
> >
> >
>
>
>
------------------------------------------------
Subject: pcp_combine with sub-hourly accumulations
From: John Halley Gotway
Time: Wed Dec 07 12:46:11 2016
Aaron,
Thanks for sending those data files. I think I see what's going on
here.
First, I ran wgrib on the data files you sent, and the output is
listed
below:
> wgrib forecast.grb | grep APCP
279:503477484:d=15062313:APCP:kpds5=61:kpds6=1:kpds7=0:TR=
10:P1=3:P2=247:TimeU=0:sfc:1015min fcst:NAve=0
> wgrib forecast2.grb | grep APCP
279:507900854:d=15062313:APCP:kpds5=61:kpds6=1:kpds7=0:TR=
10:P1=3:P2=197:TimeU=0:sfc:965min fcst:NAve=0
Notice the output which says "TR=10". TR means time range indicator
and a
value of 10 means that the level information contains an instantaneous
forecast time, not an accumulation interval. Here's a table
describing the
TR values:
http://www.nco.ncep.noaa.gov/pmb/docs/on388/table5.html
The default logic for pcp_combine is to look for GRIB code 61 (i.e.
APCP)
defined with an accumulation interval (TR = 4). Since your data
doesn't
meet that criteria, the default logic of pcp_combine won't work. We
just
need to be more specific in the arguments to tell pcp_combine exactly
what
to do.
Here's the command I'd recommend using:
met-5.2/bin/pcp_combine -subtract \
forecast.grb 'name="APCP"; level="L0"; lead_time="165500";' \
forecast2.grb 'name="APCP"; level="L0"; lead_time="160500";' \
forecast.nc -name APCP_A005000
Some things to point out here:
(1) Notice in the wgrib output that the forecast times are 1015 min
and 965
min. In HHMMSS format, that's "165500" and "160500".
(2) We can't specify an accumulation interval since your data isn't
stored
that way. Instead, I've used a config file string to describe the
data you
want to use.
(3) The config file string specifies a "name" (APCP) and "level"
string.
APCP is defined at the surface, so I specified a level value of 0
(L0).
(4) Technically, I don't need to specify the "lead_time" at all.
pcp_combine would find the single APCP record in each input GRIB file
and
use them. But I included the lead_time option to be extra certain
we're
getting exactly the data we want.
(5) The default output variable name pcp_combine would write would be
"APCP_L0". However, I chose to use a different output variable name
(APCP_A005000) to indicate that its a 50 minute "accumulation
interval".
Of course you could choose whatever string you'd like... maybe
"Precip50Minutes" or "RAIN50". It's up to you. But whatever string
you
choose will be used in the Grid-Stat, Point-Stat, or MODE config file
to
tell that tool what variable to process.
Hope that helps clarify.
Thanks,
John
------------------------------------------------
Subject: pcp_combine with sub-hourly accumulations
From: Johnson, Aaron
Time: Wed Dec 07 12:48:21 2016
John,
That is extremely helpful. Thanks!
Aaron
________________________________
From: John Halley Gotway via RT <met_help at ucar.edu>
Sent: Wednesday, December 7, 2016 1:46:12 PM
To: Johnson, Aaron
Subject: Re: [rt.rap.ucar.edu #78833] pcp_combine with sub-hourly
accumulations
Aaron,
Thanks for sending those data files. I think I see what's going on
here.
First, I ran wgrib on the data files you sent, and the output is
listed
below:
> wgrib forecast.grb | grep APCP
279:503477484:d=15062313:APCP:kpds5=61:kpds6=1:kpds7=0:TR=
10:P1=3:P2=247:TimeU=0:sfc:1015min fcst:NAve=0
> wgrib forecast2.grb | grep APCP
279:507900854:d=15062313:APCP:kpds5=61:kpds6=1:kpds7=0:TR=
10:P1=3:P2=197:TimeU=0:sfc:965min fcst:NAve=0
Notice the output which says "TR=10". TR means time range indicator
and a
value of 10 means that the level information contains an instantaneous
forecast time, not an accumulation interval. Here's a table
describing the
TR values:
http://www.nco.ncep.noaa.gov/pmb/docs/on388/table5.html
The default logic for pcp_combine is to look for GRIB code 61 (i.e.
APCP)
defined with an accumulation interval (TR = 4). Since your data
doesn't
meet that criteria, the default logic of pcp_combine won't work. We
just
need to be more specific in the arguments to tell pcp_combine exactly
what
to do.
Here's the command I'd recommend using:
met-5.2/bin/pcp_combine -subtract \
forecast.grb 'name="APCP"; level="L0"; lead_time="165500";' \
forecast2.grb 'name="APCP"; level="L0"; lead_time="160500";' \
forecast.nc -name APCP_A005000
Some things to point out here:
(1) Notice in the wgrib output that the forecast times are 1015 min
and 965
min. In HHMMSS format, that's "165500" and "160500".
(2) We can't specify an accumulation interval since your data isn't
stored
that way. Instead, I've used a config file string to describe the
data you
want to use.
(3) The config file string specifies a "name" (APCP) and "level"
string.
APCP is defined at the surface, so I specified a level value of 0
(L0).
(4) Technically, I don't need to specify the "lead_time" at all.
pcp_combine would find the single APCP record in each input GRIB file
and
use them. But I included the lead_time option to be extra certain
we're
getting exactly the data we want.
(5) The default output variable name pcp_combine would write would be
"APCP_L0". However, I chose to use a different output variable name
(APCP_A005000) to indicate that its a 50 minute "accumulation
interval".
Of course you could choose whatever string you'd like... maybe
"Precip50Minutes" or "RAIN50". It's up to you. But whatever string
you
choose will be used in the Grid-Stat, Point-Stat, or MODE config file
to
tell that tool what variable to process.
Hope that helps clarify.
Thanks,
John
------------------------------------------------
Subject: pcp_combine with sub-hourly accumulations
From: Johnson, Aaron
Time: Thu Dec 08 10:59:47 2016
Hi John,
I have another question related to this thread. If I wanted to simply
convert the composite reflectivity "REFC" in the grib file at
/incoming/irap/met_help/johnson2_data/forecast.grb into a netcdf file
for MODE, would I still use pcp_combine and what command would I use?
I am currently getting the error,
ERROR : is_prelim_match() - unrecognized GRIB1 field abbreviation
'REFC' for table version 2
for the command,
$MET_BUILD/bin/pcp_combine -add forecast.grb
'name="REFC";level="L0";lead_time="120000";'\
forecast.nc -name REFC
Also, since I will eventually want to try different variables such as
vertical velocity, or derived variables such as updraft helicity, is
there a more general or direct way to get such data into MODE without
even having to run the WRF UPP followed by pcp_combine?
Thanks for your time in helping me get started with MODE,
Aaron
________________________________
From: John Halley Gotway via RT <met_help at ucar.edu>
Sent: Wednesday, December 7, 2016 1:46:12 PM
To: Johnson, Aaron
Subject: Re: [rt.rap.ucar.edu #78833] pcp_combine with sub-hourly
accumulations
Aaron,
Thanks for sending those data files. I think I see what's going on
here.
First, I ran wgrib on the data files you sent, and the output is
listed
below:
> wgrib forecast.grb | grep APCP
279:503477484:d=15062313:APCP:kpds5=61:kpds6=1:kpds7=0:TR=
10:P1=3:P2=247:TimeU=0:sfc:1015min fcst:NAve=0
> wgrib forecast2.grb | grep APCP
279:507900854:d=15062313:APCP:kpds5=61:kpds6=1:kpds7=0:TR=
10:P1=3:P2=197:TimeU=0:sfc:965min fcst:NAve=0
Notice the output which says "TR=10". TR means time range indicator
and a
value of 10 means that the level information contains an instantaneous
forecast time, not an accumulation interval. Here's a table
describing the
TR values:
http://www.nco.ncep.noaa.gov/pmb/docs/on388/table5.html
GRIB - National Oceanic and Atmospheric
Administration<http://www.nco.ncep.noaa.gov/pmb/docs/on388/table5.html>
www.nco.ncep.noaa.gov
NOTES: 1) For analysis products, or the first of a series of analysis
products, the reference time (octets 13 to 17) indicates the valid
time. 2) For forecast ...
The default logic for pcp_combine is to look for GRIB code 61 (i.e.
APCP)
defined with an accumulation interval (TR = 4). Since your data
doesn't
meet that criteria, the default logic of pcp_combine won't work. We
just
need to be more specific in the arguments to tell pcp_combine exactly
what
to do.
Here's the command I'd recommend using:
met-5.2/bin/pcp_combine -subtract \
forecast.grb 'name="APCP"; level="L0"; lead_time="165500";' \
forecast2.grb 'name="APCP"; level="L0"; lead_time="160500";' \
forecast.nc -name APCP_A005000
Some things to point out here:
(1) Notice in the wgrib output that the forecast times are 1015 min
and 965
min. In HHMMSS format, that's "165500" and "160500".
(2) We can't specify an accumulation interval since your data isn't
stored
that way. Instead, I've used a config file string to describe the
data you
want to use.
(3) The config file string specifies a "name" (APCP) and "level"
string.
APCP is defined at the surface, so I specified a level value of 0
(L0).
(4) Technically, I don't need to specify the "lead_time" at all.
pcp_combine would find the single APCP record in each input GRIB file
and
use them. But I included the lead_time option to be extra certain
we're
getting exactly the data we want.
(5) The default output variable name pcp_combine would write would be
"APCP_L0". However, I chose to use a different output variable name
(APCP_A005000) to indicate that its a 50 minute "accumulation
interval".
Of course you could choose whatever string you'd like... maybe
"Precip50Minutes" or "RAIN50". It's up to you. But whatever string
you
choose will be used in the Grid-Stat, Point-Stat, or MODE config file
to
tell that tool what variable to process.
Hope that helps clarify.
Thanks,
John
------------------------------------------------
Subject: pcp_combine with sub-hourly accumulations
From: John Halley Gotway
Time: Thu Dec 08 12:18:47 2016
Aaron,
First, it is not necessary to convert GRIB to NetCDF prior to running
MODE. MODE can take as input any of the gridded file formats that MET
supports, such as GRIB1, GRIB2, and a few flavors of NetCDF. The only
difference is how you set up the MODE config file to indicate what
data
you'd like it to read.
Second, composite reflectivity (REFC) is defined in GRIB parameter
table
version number 129. You can make this work by specifying that
information. Try running this command:
$MET_BUILD/bin/plot_data_plane forecast.grb refc.ps 'name="REFC";
level="L0"; GRIB1_ptv=129;'
That will extract the REFC record and create a PostScript plot of it.
Notice that the "GRIB1_ptv=129;" specifies the parameter table version
number.
Honestly, I'm surprised this issue came up. I thought in MET version
5.2
we'd made the code smart enough to not need GRIB1_ptv, but clearly I'm
mistaken. I'll take a closer look to see if we can remove the need
for
that in version 6.0 of MET.
While it is not necessary to convert to NetCDF prior to running MODE,
if
you find it preferable for some reason, you certainly can do that.
And
yes, I would use the pcp_combine "-add" option to do that:
$MET_BUILD/bin/pcp_combine -add forecast.grb 'name="REFC";
level="L0";
GRIB1_ptv=129; lead_time="120000";' forecast.nc -name REFC
Thanks,
John
On Thu, Dec 8, 2016 at 10:59 AM, Johnson, Aaron via RT
<met_help at ucar.edu>
wrote:
>
> <URL: https://rt.rap.ucar.edu/rt/Ticket/Display.html?id=78833 >
>
>
> Hi John,
>
> I have another question related to this thread. If I wanted to
simply
> convert the composite reflectivity "REFC" in the grib file at
> /incoming/irap/met_help/johnson2_data/forecast.grb into a netcdf
file for
> MODE, would I still use pcp_combine and what command would I use? I
am
> currently getting the error,
>
> ERROR : is_prelim_match() - unrecognized GRIB1 field abbreviation
'REFC'
> for table version 2
>
> for the command,
>
> $MET_BUILD/bin/pcp_combine -add forecast.grb
'name="REFC";level="L0";lead_t
> ime="120000";'\
>
> forecast.nc -name REFC
>
>
> Also, since I will eventually want to try different variables such
as
> vertical velocity, or derived variables such as updraft helicity, is
there
> a more general or direct way to get such data into MODE without even
having
> to run the WRF UPP followed by pcp_combine?
>
> Thanks for your time in helping me get started with MODE,
>
> Aaron
>
> ________________________________
> From: John Halley Gotway via RT <met_help at ucar.edu>
> Sent: Wednesday, December 7, 2016 1:46:12 PM
> To: Johnson, Aaron
> Subject: Re: [rt.rap.ucar.edu #78833] pcp_combine with sub-hourly
> accumulations
>
> Aaron,
>
> Thanks for sending those data files. I think I see what's going on
here.
> First, I ran wgrib on the data files you sent, and the output is
listed
> below:
>
> > wgrib forecast.grb | grep APCP
> 279:503477484:d=15062313:APCP:kpds5=61:kpds6=1:kpds7=0:TR=
> 10:P1=3:P2=247:TimeU=0:sfc:1015min fcst:NAve=0
> > wgrib forecast2.grb | grep APCP
> 279:507900854:d=15062313:APCP:kpds5=61:kpds6=1:kpds7=0:TR=
> 10:P1=3:P2=197:TimeU=0:sfc:965min fcst:NAve=0
>
> Notice the output which says "TR=10". TR means time range indicator
and a
> value of 10 means that the level information contains an
instantaneous
> forecast time, not an accumulation interval. Here's a table
describing the
> TR values:
> http://www.nco.ncep.noaa.gov/pmb/docs/on388/table5.html
> GRIB - National Oceanic and Atmospheric
Administration<http://www.nco.
> ncep.noaa.gov/pmb/docs/on388/table5.html>
> www.nco.ncep.noaa.gov
> NOTES: 1) For analysis products, or the first of a series of
analysis
> products, the reference time (octets 13 to 17) indicates the valid
time. 2)
> For forecast ...
>
>
>
>
> The default logic for pcp_combine is to look for GRIB code 61 (i.e.
APCP)
> defined with an accumulation interval (TR = 4). Since your data
doesn't
> meet that criteria, the default logic of pcp_combine won't work. We
just
> need to be more specific in the arguments to tell pcp_combine
exactly what
> to do.
>
> Here's the command I'd recommend using:
>
> met-5.2/bin/pcp_combine -subtract \
> forecast.grb 'name="APCP"; level="L0"; lead_time="165500";' \
> forecast2.grb 'name="APCP"; level="L0"; lead_time="160500";' \
> forecast.nc -name APCP_A005000
>
> Some things to point out here:
> (1) Notice in the wgrib output that the forecast times are 1015 min
and 965
> min. In HHMMSS format, that's "165500" and "160500".
> (2) We can't specify an accumulation interval since your data isn't
stored
> that way. Instead, I've used a config file string to describe the
data you
> want to use.
> (3) The config file string specifies a "name" (APCP) and "level"
string.
> APCP is defined at the surface, so I specified a level value of 0
(L0).
> (4) Technically, I don't need to specify the "lead_time" at all.
> pcp_combine would find the single APCP record in each input GRIB
file and
> use them. But I included the lead_time option to be extra certain
we're
> getting exactly the data we want.
> (5) The default output variable name pcp_combine would write would
be
> "APCP_L0". However, I chose to use a different output variable name
> (APCP_A005000) to indicate that its a 50 minute "accumulation
interval".
> Of course you could choose whatever string you'd like... maybe
> "Precip50Minutes" or "RAIN50". It's up to you. But whatever string
you
> choose will be used in the Grid-Stat, Point-Stat, or MODE config
file to
> tell that tool what variable to process.
>
> Hope that helps clarify.
>
> Thanks,
> John
>
>
>
------------------------------------------------
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