[Met_help] [rt.rap.ucar.edu #80604] History for Question about radar reflectivity observations (UNCLASSIFIED)
Julie Prestopnik via RT
met_help at ucar.edu
Thu Jun 1 15:00:07 MDT 2017
----------------------------------------------------------------
Initial Request
----------------------------------------------------------------
CLASSIFICATION: UNCLASSIFIED
I will be using radar obs to verify modeled radar reflectivity. The
reflectivity obs are in CF-compliant NetCDF format. I'm trying to understand
the "level" entry for the field in the config file.
An example from the Config file overview text file is on P10 which shows the
"name" and "level" entries for the variable called "QVAPOR". What I would
like to do is to be able to explore the model output (GRIB) for the same
variable (SPFH) using wgrib -v and use the grid information in this listing
to derive the corresponding "dimension values" which are the equivalent for
the QVAPOR observations in NetCDF format. For example:
How can I relate the level information for QVAPOR which is "(0,5,*,*)" to
the level information for SPFH as shown by wgrib -v? If this isn't possible
and you have to explore the NetCDF file itself, then maybe you could provide
some explanation of the "level" entry so I can pick out from the ncdump of
the NetCDF file the info necessary to provide the dimensions in the "level"
entry.
Using this understanding I hope to determine the correct level dimensions
for the radar observations.
Thanks.
R/
John
Mr John W. Raby, Meteorologist
U.S. Army Research Laboratory
White Sands Missile Range, NM 88002
(575) 678-2004 DSN 258-2004
FAX (575) 678-1230 DSN 258-1230
Email: john.w.raby2.civ at mail.mil
CLASSIFICATION: UNCLASSIFIED
----------------------------------------------------------------
Complete Ticket History
----------------------------------------------------------------
Subject: Question about radar reflectivity observations (UNCLASSIFIED)
From: Randy Bullock
Time: Thu May 25 09:49:42 2017
John -
Just a quick heads up: most of our team is out for the memorial day
weekend, so any work on this issue will likely have to wait until next
week
sometime.
FYI
Randy Bullock
On Wed, May 24, 2017 at 3:25 PM, Raby, John W USA CIV via RT <
met_help at ucar.edu> wrote:
>
> Wed May 24 15:25:55 2017: Request 80604 was acted upon.
> Transaction: Ticket created by john.w.raby2.civ at mail.mil
> Queue: met_help
> Subject: Question about radar reflectivity observations
(UNCLASSIFIED)
> Owner: Nobody
> Requestors: john.w.raby2.civ at mail.mil
> Status: new
> Ticket <URL:
https://rt.rap.ucar.edu/rt/Ticket/Display.html?id=80604 >
>
>
> CLASSIFICATION: UNCLASSIFIED
>
> I will be using radar obs to verify modeled radar reflectivity. The
> reflectivity obs are in CF-compliant NetCDF format. I'm trying to
> understand
> the "level" entry for the field in the config file.
>
> An example from the Config file overview text file is on P10 which
shows
> the
> "name" and "level" entries for the variable called "QVAPOR". What I
would
> like to do is to be able to explore the model output (GRIB) for the
same
> variable (SPFH) using wgrib -v and use the grid information in this
listing
> to derive the corresponding "dimension values" which are the
equivalent for
> the QVAPOR observations in NetCDF format. For example:
>
> How can I relate the level information for QVAPOR which is
"(0,5,*,*)" to
> the level information for SPFH as shown by wgrib -v? If this isn't
possible
> and you have to explore the NetCDF file itself, then maybe you could
> provide
> some explanation of the "level" entry so I can pick out from the
ncdump of
> the NetCDF file the info necessary to provide the dimensions in the
"level"
> entry.
>
> Using this understanding I hope to determine the correct level
dimensions
> for the radar observations.
>
> Thanks.
>
> R/
> John
>
> Mr John W. Raby, Meteorologist
> U.S. Army Research Laboratory
> White Sands Missile Range, NM 88002
> (575) 678-2004 DSN 258-2004
> FAX (575) 678-1230 DSN 258-1230
> Email: john.w.raby2.civ at mail.mil
>
>
> CLASSIFICATION: UNCLASSIFIED
>
>
------------------------------------------------
Subject: Question about radar reflectivity observations (UNCLASSIFIED)
From: Raby, John W USA CIV
Time: Wed May 31 07:28:13 2017
CLASSIFICATION: UNCLASSIFIED
Randy -
Thanks for the update. This week is fine for me.
R/
John
-----Original Message-----
From: Randy Bullock via RT [mailto:met_help at ucar.edu]
Sent: Thursday, May 25, 2017 9:50 AM
To: Raby, John W CIV USARMY RDECOM ARL (US)
<john.w.raby2.civ at mail.mil>
Subject: [Non-DoD Source] Re: [rt.rap.ucar.edu #80604] Question about
radar
reflectivity observations (UNCLASSIFIED)
All active links contained in this email were disabled. Please verify
the
identity of the sender, and confirm the authenticity of all links
contained
within the message prior to copying and pasting the address to a Web
browser.
----
John -
Just a quick heads up: most of our team is out for the memorial day
weekend,
so any work on this issue will likely have to wait until next week
sometime.
FYI
Randy Bullock
On Wed, May 24, 2017 at 3:25 PM, Raby, John W USA CIV via RT <
met_help at ucar.edu> wrote:
>
> Wed May 24 15:25:55 2017: Request 80604 was acted upon.
> Transaction: Ticket created by john.w.raby2.civ at mail.mil
> Queue: met_help
> Subject: Question about radar reflectivity observations
(UNCLASSIFIED)
> Owner: Nobody
> Requestors: john.w.raby2.civ at mail.mil
> Status: new
> Ticket <Caution-url:
> Caution-https://rt.rap.ucar.edu/rt/Ticket/Display.html?id=80604 >
>
>
> CLASSIFICATION: UNCLASSIFIED
>
> I will be using radar obs to verify modeled radar reflectivity. The
> reflectivity obs are in CF-compliant NetCDF format. I'm trying to
> understand the "level" entry for the field in the config file.
>
> An example from the Config file overview text file is on P10 which
> shows the "name" and "level" entries for the variable called
"QVAPOR".
> What I would like to do is to be able to explore the model output
> (GRIB) for the same variable (SPFH) using wgrib -v and use the grid
> information in this listing to derive the corresponding "dimension
> values" which are the equivalent for the QVAPOR observations in
NetCDF
> format. For example:
>
> How can I relate the level information for QVAPOR which is
"(0,5,*,*)"
> to the level information for SPFH as shown by wgrib -v? If this
isn't
> possible and you have to explore the NetCDF file itself, then maybe
> you could provide some explanation of the "level" entry so I can
pick
> out from the ncdump of the NetCDF file the info necessary to provide
> the dimensions in the "level"
> entry.
>
> Using this understanding I hope to determine the correct level
> dimensions for the radar observations.
>
> Thanks.
>
> R/
> John
>
> Mr John W. Raby, Meteorologist
> U.S. Army Research Laboratory
> White Sands Missile Range, NM 88002
> (575) 678-2004 DSN 258-2004
> FAX (575) 678-1230 DSN 258-1230
> Email: john.w.raby2.civ at mail.mil
>
>
> CLASSIFICATION: UNCLASSIFIED
>
>
CLASSIFICATION: UNCLASSIFIED
------------------------------------------------
Subject: Question about radar reflectivity observations (UNCLASSIFIED)
From: Julie Prestopnik
Time: Wed May 31 14:44:44 2017
Hi John. I see that you are trying to understand the "level" entry
for the
field in the configuration files. While I am certain John is the best
person to answer your question, he is out until next week, so I will
do
what I can to answer your question as best as I can.
In the MET User's Guide for version 6.0:
http://www.dtcenter.org/met/users/docs/users_guide/MET_Users_Guide_v6.0.pdf
On page 53, the "level" entry for the "field" entry is described.
Please
refer to that page starting at " File-format specific settings for the
"field" entry:"
More specifically, I grabbed a random GFS GRIB file and ran "wgrib -v"
and
grepped for "SPFH" and see the following:
219:85753384:D=2012040900:SPFH:2 m above gnd:kpds=51,105,2:51hr
fcst:winds
are N/S:"Specific humidity [kg/kg]
In this case you would use level="Z2" to specify the vertical level.
I hope that helps! Please let us know how it goes and if you need
further
assistance.
Thanks,
Julie
On Wed, May 24, 2017 at 3:25 PM, Raby, John W USA CIV via RT <
met_help at ucar.edu> wrote:
>
> Wed May 24 15:25:55 2017: Request 80604 was acted upon.
> Transaction: Ticket created by john.w.raby2.civ at mail.mil
> Queue: met_help
> Subject: Question about radar reflectivity observations
(UNCLASSIFIED)
> Owner: Nobody
> Requestors: john.w.raby2.civ at mail.mil
> Status: new
> Ticket <URL:
https://rt.rap.ucar.edu/rt/Ticket/Display.html?id=80604 >
>
>
> CLASSIFICATION: UNCLASSIFIED
>
> I will be using radar obs to verify modeled radar reflectivity. The
> reflectivity obs are in CF-compliant NetCDF format. I'm trying to
> understand
> the "level" entry for the field in the config file.
>
> An example from the Config file overview text file is on P10 which
shows
> the
> "name" and "level" entries for the variable called "QVAPOR". What I
would
> like to do is to be able to explore the model output (GRIB) for the
same
> variable (SPFH) using wgrib -v and use the grid information in this
listing
> to derive the corresponding "dimension values" which are the
equivalent for
> the QVAPOR observations in NetCDF format. For example:
>
> How can I relate the level information for QVAPOR which is
"(0,5,*,*)" to
> the level information for SPFH as shown by wgrib -v? If this isn't
possible
> and you have to explore the NetCDF file itself, then maybe you could
> provide
> some explanation of the "level" entry so I can pick out from the
ncdump of
> the NetCDF file the info necessary to provide the dimensions in the
"level"
> entry.
>
> Using this understanding I hope to determine the correct level
dimensions
> for the radar observations.
>
> Thanks.
>
> R/
> John
>
> Mr John W. Raby, Meteorologist
> U.S. Army Research Laboratory
> White Sands Missile Range, NM 88002
> (575) 678-2004 DSN 258-2004
> FAX (575) 678-1230 DSN 258-1230
> Email: john.w.raby2.civ at mail.mil
>
>
> CLASSIFICATION: UNCLASSIFIED
>
>
------------------------------------------------
Subject: Question about radar reflectivity observations (UNCLASSIFIED)
From: Raby, John W USA CIV
Time: Wed May 31 15:17:59 2017
CLASSIFICATION: UNCLASSIFIED
Hi Julie -
Thanks for addressing my question.
I looked at p.53 and it describes the level entry if you were using
GRIB
formatted files. In the case of the radar observations, the format
will be
NetCDF (CF-compliant). I looked at p.54 where it does talk about those
entries
which are notably different from those used for GRIB files. I cited
the
example shown on this page (54) for the variable "QVAPOR" in my email
below
thinking that SPFH which is present in a GRIB file would be analogous
to
QVAPOR and thus might be an easy way to determine the "level" values
(Z2 for
GRIB) and then convert it to the equivalent "level" entry for a NetCDF
file.
I'm also a little confused about the other part of the "level" entry
for
NetCDF which is called "dimensions". Using wgrib -v or some other
option one
should be able to determine what the "dimension" is as well as the
level. At
least, that's what I think and I am no expert on this. It may be that
this
information can't be determined by exploring the GRIB file equivalent
of
QVAPOR and you must explore the NetCDF file instead to find it out.
Unfortunately, I don't have a NetCDF file for my radar obs yet, so I
can't
explore them yet, but there must be other NetCDF output which could be
used.
An example could be the output of the Pcp_Combine tool which is a
gridded
NetCDF file which is input into Grid-Stat for either the observation
file or
the fcst file or both. The same "level" entry would have to be
specified in
the Grid-Stat config file in order for it to read the NetCDF input
files.
This can certainly wait until next week when John gets back on this,
so don't
go to great lengths to provide an answer now.
R/
John
-----Original Message-----
From: Julie Prestopnik via RT [mailto:met_help at ucar.edu]
Sent: Wednesday, May 31, 2017 2:45 PM
To: Raby, John W CIV USARMY RDECOM ARL (US)
<john.w.raby2.civ at mail.mil>
Subject: [Non-DoD Source] Re: [rt.rap.ucar.edu #80604] Question about
radar
reflectivity observations (UNCLASSIFIED)
All active links contained in this email were disabled. Please verify
the
identity of the sender, and confirm the authenticity of all links
contained
within the message prior to copying and pasting the address to a Web
browser.
----
Hi John. I see that you are trying to understand the "level" entry
for the
field in the configuration files. While I am certain John is the best
person
to answer your question, he is out until next week, so I will do what
I can to
answer your question as best as I can.
In the MET User's Guide for version 6.0:
Caution-
http://www.dtcenter.org/met/users/docs/users_guide/MET_Users_Guide_v6.0.pdf
On page 53, the "level" entry for the "field" entry is described.
Please refer
to that page starting at " File-format specific settings for the
"field"
entry:"
More specifically, I grabbed a random GFS GRIB file and ran "wgrib -v"
and
grepped for "SPFH" and see the following:
219:85753384:D=2012040900:SPFH:2 m above gnd:kpds=51,105,2:51hr
fcst:winds are
N/S:"Specific humidity [kg/kg]
In this case you would use level="Z2" to specify the vertical level.
I hope that helps! Please let us know how it goes and if you need
further
assistance.
Thanks,
Julie
On Wed, May 24, 2017 at 3:25 PM, Raby, John W USA CIV via RT <
met_help at ucar.edu> wrote:
>
> Wed May 24 15:25:55 2017: Request 80604 was acted upon.
> Transaction: Ticket created by john.w.raby2.civ at mail.mil
> Queue: met_help
> Subject: Question about radar reflectivity observations
(UNCLASSIFIED)
> Owner: Nobody
> Requestors: john.w.raby2.civ at mail.mil
> Status: new
> Ticket <Caution-url:
> Caution-https://rt.rap.ucar.edu/rt/Ticket/Display.html?id=80604 >
>
>
> CLASSIFICATION: UNCLASSIFIED
>
> I will be using radar obs to verify modeled radar reflectivity. The
> reflectivity obs are in CF-compliant NetCDF format. I'm trying to
> understand the "level" entry for the field in the config file.
>
> An example from the Config file overview text file is on P10 which
> shows the "name" and "level" entries for the variable called
"QVAPOR".
> What I would like to do is to be able to explore the model output
> (GRIB) for the same variable (SPFH) using wgrib -v and use the grid
> information in this listing to derive the corresponding "dimension
> values" which are the equivalent for the QVAPOR observations in
NetCDF
> format. For example:
>
> How can I relate the level information for QVAPOR which is
"(0,5,*,*)"
> to the level information for SPFH as shown by wgrib -v? If this
isn't
> possible and you have to explore the NetCDF file itself, then maybe
> you could provide some explanation of the "level" entry so I can
pick
> out from the ncdump of the NetCDF file the info necessary to provide
> the dimensions in the "level"
> entry.
>
> Using this understanding I hope to determine the correct level
> dimensions for the radar observations.
>
> Thanks.
>
> R/
> John
>
> Mr John W. Raby, Meteorologist
> U.S. Army Research Laboratory
> White Sands Missile Range, NM 88002
> (575) 678-2004 DSN 258-2004
> FAX (575) 678-1230 DSN 258-1230
> Email: john.w.raby2.civ at mail.mil
>
>
> CLASSIFICATION: UNCLASSIFIED
>
>
CLASSIFICATION: UNCLASSIFIED
------------------------------------------------
Subject: Question about radar reflectivity observations (UNCLASSIFIED)
From: Julie Prestopnik
Time: Thu Jun 01 10:24:56 2017
Hi John. I had misunderstood what you were asking, but I think I
better
understand now.
I put two files on our ftp server (ftp.rap.ucar.edu) for you at
pub/jpresto/for_raby/.
The files are:
20170601_i12_f002_WRF-RR.grb2
20170601_i12_f002_WRF-RR.nc
When I run, "wgrib2 -v 20170601_i12_f002_WRF-RR.grb2 | grep SPFH", I
get
the following for the 3D SPFH var:
16:637394:d=2017060112:SPFH Specific Humidity [kg/kg]:1 hybrid level:2
hour
fcst:
35:1709666:d=2017060112:SPFH Specific Humidity [kg/kg]:2 hybrid
level:2
hour fcst:
54:2823255:d=2017060112:SPFH Specific Humidity [kg/kg]:3 hybrid
level:2
hour fcst:
... (with levels 4 - 47)
909:42584590:d=2017060112:SPFH Specific Humidity [kg/kg]:48 hybrid
level:2
hour fcst:
928:43216366:d=2017060112:SPFH Specific Humidity [kg/kg]:49 hybrid
level:2
hour fcst:
947:43826690:d=2017060112:SPFH Specific Humidity [kg/kg]:50 hybrid
level:2
hour fcst:
This netcdf file has been paired down (only some of the vars) and put
in a
CF compliant format. Likewise, when I run "ncdump -h
20170601_i12_f002_WRF-RR.nc | grep SPFH", I see the following:
float SPFH_P0_L105_GLC0(time, lv_HYBL1, y, x) ;
SPFH_P0_L105_GLC0:level_type = "Hybrid level" ;
SPFH_P0_L105_GLC0:parameter_template_discipline_category_number = 0,
0, 1,
0 ;
SPFH_P0_L105_GLC0:parameter_discipline_and_category =
"Meteorological products, Moisture" ;
SPFH_P0_L105_GLC0:grid_mapping = "grid_mapping" ;
SPFH_P0_L105_GLC0:coordinates = "lat lon" ;
SPFH_P0_L105_GLC0:_FillValue = 1.e+20f ;
SPFH_P0_L105_GLC0:units = "kg kg-1" ;
SPFH_P0_L105_GLC0:long_name = "Specific humidity" ;
SPFH_P0_L105_GLC0:production_status = "Research
products" ;
SPFH_P0_L105_GLC0:center = "NOAA Forecast Systems Lab,
Boulder CO" ;
There is only one time present in this file, so if you wanted to
explore
the 45th hybrid level, I believe you would use "(0,44,*,*)". It would
be
"44" instead of "45" because of the 0 indexing (starting with 0 as
opposed
to 1).
I hope this is helpful. Please let me know if you have other
questions.
Also, once you have your NetCDF file with your radar obs, let us know
if we
can help with your specific situation.
Thanks,
Julie
On Wed, May 31, 2017 at 3:17 PM, Raby, John W USA CIV via RT <
met_help at ucar.edu> wrote:
>
> <URL: https://rt.rap.ucar.edu/rt/Ticket/Display.html?id=80604 >
>
> CLASSIFICATION: UNCLASSIFIED
>
> Hi Julie -
>
> Thanks for addressing my question.
>
> I looked at p.53 and it describes the level entry if you were using
GRIB
> formatted files. In the case of the radar observations, the format
will be
> NetCDF (CF-compliant). I looked at p.54 where it does talk about
those
> entries
> which are notably different from those used for GRIB files. I cited
the
> example shown on this page (54) for the variable "QVAPOR" in my
email below
> thinking that SPFH which is present in a GRIB file would be
analogous to
> QVAPOR and thus might be an easy way to determine the "level" values
(Z2
> for
> GRIB) and then convert it to the equivalent "level" entry for a
NetCDF
> file.
> I'm also a little confused about the other part of the "level" entry
for
> NetCDF which is called "dimensions". Using wgrib -v or some other
option
> one
> should be able to determine what the "dimension" is as well as the
level.
> At
> least, that's what I think and I am no expert on this. It may be
that this
> information can't be determined by exploring the GRIB file
equivalent of
> QVAPOR and you must explore the NetCDF file instead to find it out.
> Unfortunately, I don't have a NetCDF file for my radar obs yet, so I
can't
> explore them yet, but there must be other NetCDF output which could
be
> used.
> An example could be the output of the Pcp_Combine tool which is a
gridded
> NetCDF file which is input into Grid-Stat for either the observation
file
> or
> the fcst file or both. The same "level" entry would have to be
specified in
> the Grid-Stat config file in order for it to read the NetCDF input
files.
>
> This can certainly wait until next week when John gets back on this,
so
> don't
> go to great lengths to provide an answer now.
>
> R/
> John
>
> -----Original Message-----
> From: Julie Prestopnik via RT [mailto:met_help at ucar.edu]
> Sent: Wednesday, May 31, 2017 2:45 PM
> To: Raby, John W CIV USARMY RDECOM ARL (US)
<john.w.raby2.civ at mail.mil>
> Subject: [Non-DoD Source] Re: [rt.rap.ucar.edu #80604] Question
about
> radar
> reflectivity observations (UNCLASSIFIED)
>
> All active links contained in this email were disabled. Please
verify the
> identity of the sender, and confirm the authenticity of all links
contained
> within the message prior to copying and pasting the address to a Web
> browser.
>
>
>
>
> ----
>
> Hi John. I see that you are trying to understand the "level" entry
for the
> field in the configuration files. While I am certain John is the
best
> person
> to answer your question, he is out until next week, so I will do
what I
> can to
> answer your question as best as I can.
>
> In the MET User's Guide for version 6.0:
> Caution-http://www.dtcenter.org/met/users/docs/users_
> guide/MET_Users_Guide_v6.0.pdf
>
> On page 53, the "level" entry for the "field" entry is described.
Please
> refer
> to that page starting at " File-format specific settings for the
"field"
> entry:"
>
> More specifically, I grabbed a random GFS GRIB file and ran "wgrib
-v" and
> grepped for "SPFH" and see the following:
>
> 219:85753384:D=2012040900:SPFH:2 m above gnd:kpds=51,105,2:51hr
> fcst:winds are
> N/S:"Specific humidity [kg/kg]
>
> In this case you would use level="Z2" to specify the vertical level.
>
> I hope that helps! Please let us know how it goes and if you need
further
> assistance.
>
> Thanks,
> Julie
>
>
>
> On Wed, May 24, 2017 at 3:25 PM, Raby, John W USA CIV via RT <
> met_help at ucar.edu> wrote:
>
> >
> > Wed May 24 15:25:55 2017: Request 80604 was acted upon.
> > Transaction: Ticket created by john.w.raby2.civ at mail.mil
> > Queue: met_help
> > Subject: Question about radar reflectivity observations
> (UNCLASSIFIED)
> > Owner: Nobody
> > Requestors: john.w.raby2.civ at mail.mil
> > Status: new
> > Ticket <Caution-url:
> > Caution-https://rt.rap.ucar.edu/rt/Ticket/Display.html?id=80604 >
> >
> >
> > CLASSIFICATION: UNCLASSIFIED
> >
> > I will be using radar obs to verify modeled radar reflectivity.
The
> > reflectivity obs are in CF-compliant NetCDF format. I'm trying to
> > understand the "level" entry for the field in the config file.
> >
> > An example from the Config file overview text file is on P10 which
> > shows the "name" and "level" entries for the variable called
"QVAPOR".
> > What I would like to do is to be able to explore the model output
> > (GRIB) for the same variable (SPFH) using wgrib -v and use the
grid
> > information in this listing to derive the corresponding "dimension
> > values" which are the equivalent for the QVAPOR observations in
NetCDF
> > format. For example:
> >
> > How can I relate the level information for QVAPOR which is
"(0,5,*,*)"
> > to the level information for SPFH as shown by wgrib -v? If this
isn't
> > possible and you have to explore the NetCDF file itself, then
maybe
> > you could provide some explanation of the "level" entry so I can
pick
> > out from the ncdump of the NetCDF file the info necessary to
provide
> > the dimensions in the "level"
> > entry.
> >
> > Using this understanding I hope to determine the correct level
> > dimensions for the radar observations.
> >
> > Thanks.
> >
> > R/
> > John
> >
> > Mr John W. Raby, Meteorologist
> > U.S. Army Research Laboratory
> > White Sands Missile Range, NM 88002
> > (575) 678-2004 DSN 258-2004
> > FAX (575) 678-1230 DSN 258-1230
> > Email: john.w.raby2.civ at mail.mil
> >
> >
> > CLASSIFICATION: UNCLASSIFIED
> >
> >
>
>
> CLASSIFICATION: UNCLASSIFIED
>
>
------------------------------------------------
Subject: Question about radar reflectivity observations (UNCLASSIFIED)
From: Raby, John W USA CIV
Time: Thu Jun 01 13:01:35 2017
CLASSIFICATION: UNCLASSIFIED
Julie -
Thanks for this information. It really helps. I'm seeing that the info
contained in the dump of the NetCDF file specifically allows you to
determine
the correct level value. This comes from the line in the ncdump output
which
starts with the word "float". I see the string in that line "(time,
lv_HYBL1,
y, x)" which appears to correspond with the format for the Grid-Stat
config
file setting for the level information exactly. So for your example
below
"(0,44,*,*)" I assume that the following mapping is true:
time = 0
lv_HYBL44 = 44
y = * grid field dimension in the y-direction
x = * grid field dimension in the x-direction
Does the use of "*" act like a wildcard so that it will accept any
grid
dimensions?
I'll work on gaining access to your ftp site to retrieve the file you
placed
there, but I may have to get an exception to the ftp blocking in
place. I
tried to find a NetCDF file I could explore to familiarize myself by
looking
in the MET (V5.2) install dir. I found one which was produced by the
pcp-combine tool, but it was generated using MET V4.1 which doesn't
show the
line and the string "(time, lv_HYBL1, y, x)". MY guess is that it has
to be a
CF-compliant NetCDF file to use that string.
R/
John
-----Original Message-----
From: Julie Prestopnik via RT [mailto:met_help at ucar.edu]
Sent: Thursday, June 01, 2017 10:25 AM
To: Raby, John W CIV USARMY RDECOM ARL (US)
<john.w.raby2.civ at mail.mil>
Subject: Re: [Non-DoD Source] Re: [rt.rap.ucar.edu #80604] Question
about
radar reflectivity observations (UNCLASSIFIED)
All active links contained in this email were disabled. Please verify
the
identity of the sender, and confirm the authenticity of all links
contained
within the message prior to copying and pasting the address to a Web
browser.
----
Hi John. I had misunderstood what you were asking, but I think I
better
understand now.
I put two files on our ftp server (Caution-ftp.rap.ucar.edu) for you
at
pub/jpresto/for_raby/.
The files are:
20170601_i12_f002_WRF-RR.grb2
20170601_i12_f002_WRF-RR.nc
When I run, "wgrib2 -v 20170601_i12_f002_WRF-RR.grb2 | grep SPFH", I
get the
following for the 3D SPFH var:
16:637394:d=2017060112:SPFH Specific Humidity [kg/kg]:1 hybrid level:2
hour
fcst:
35:1709666:d=2017060112:SPFH Specific Humidity [kg/kg]:2 hybrid
level:2 hour
fcst:
54:2823255:d=2017060112:SPFH Specific Humidity [kg/kg]:3 hybrid
level:2 hour
fcst:
... (with levels 4 - 47)
909:42584590:d=2017060112:SPFH Specific Humidity [kg/kg]:48 hybrid
level:2
hour fcst:
928:43216366:d=2017060112:SPFH Specific Humidity [kg/kg]:49 hybrid
level:2
hour fcst:
947:43826690:d=2017060112:SPFH Specific Humidity [kg/kg]:50 hybrid
level:2
hour fcst:
This netcdf file has been paired down (only some of the vars) and put
in a CF
compliant format. Likewise, when I run "ncdump -h
20170601_i12_f002_WRF-RR.nc
| grep SPFH", I see the following:
float SPFH_P0_L105_GLC0(time, lv_HYBL1, y, x) ;
SPFH_P0_L105_GLC0:level_type = "Hybrid level" ;
SPFH_P0_L105_GLC0:parameter_template_discipline_category_number = 0,
0, 1,
0 ;
SPFH_P0_L105_GLC0:parameter_discipline_and_category =
"Meteorological products, Moisture" ;
SPFH_P0_L105_GLC0:grid_mapping = "grid_mapping" ;
SPFH_P0_L105_GLC0:coordinates = "lat lon" ;
SPFH_P0_L105_GLC0:_FillValue = 1.e+20f ;
SPFH_P0_L105_GLC0:units = "kg kg-1" ;
SPFH_P0_L105_GLC0:long_name = "Specific humidity" ;
SPFH_P0_L105_GLC0:production_status = "Research
products" ;
SPFH_P0_L105_GLC0:center = "NOAA Forecast Systems Lab,
Boulder
CO" ;-
There is only one time present in this file, so if you wanted to
explore the
45th hybrid level, I believe you would use "(0,44,*,*)". It would be
"44"
instead of "45" because of the 0 indexing (starting with 0 as opposed
to 1).
I hope this is helpful. Please let me know if you have other
questions.
Also, once you have your NetCDF file with your radar obs, let us know
if we
can help with your specific situation.
Thanks,
Julie
On Wed, May 31, 2017 at 3:17 PM, Raby, John W USA CIV via RT <
met_help at ucar.edu> wrote:
>
> <Caution-url:
> Caution-https://rt.rap.ucar.edu/rt/Ticket/Display.html?id=80604 >
>
> CLASSIFICATION: UNCLASSIFIED
>
> Hi Julie -
>
> Thanks for addressing my question.
>
> I looked at p.53 and it describes the level entry if you were using
> GRIB formatted files. In the case of the radar observations, the
> format will be NetCDF (CF-compliant). I looked at p.54 where it does
> talk about those entries which are notably different from those used
> for GRIB files. I cited the example shown on this page (54) for the
> variable "QVAPOR" in my email below thinking that SPFH which is
> present in a GRIB file would be analogous to QVAPOR and thus might
be
> an easy way to determine the "level" values (Z2 for
> GRIB) and then convert it to the equivalent "level" entry for a
NetCDF
> file.
> I'm also a little confused about the other part of the "level" entry
> for NetCDF which is called "dimensions". Using wgrib -v or some
other
> option one should be able to determine what the "dimension" is as
well
> as the level.
> At
> least, that's what I think and I am no expert on this. It may be
that
> this information can't be determined by exploring the GRIB file
> equivalent of QVAPOR and you must explore the NetCDF file instead to
find it
> out.
> Unfortunately, I don't have a NetCDF file for my radar obs yet, so I
> can't explore them yet, but there must be other NetCDF output which
> could be used.
> An example could be the output of the Pcp_Combine tool which is a
> gridded NetCDF file which is input into Grid-Stat for either the
> observation file or the fcst file or both. The same "level" entry
> would have to be specified in the Grid-Stat config file in order for
> it to read the NetCDF input files.
>
> This can certainly wait until next week when John gets back on this,
> so don't go to great lengths to provide an answer now.
>
> R/
> John
>
> -----Original Message-----
> From: Julie Prestopnik via RT [Caution-mailto:met_help at ucar.edu]
> Sent: Wednesday, May 31, 2017 2:45 PM
> To: Raby, John W CIV USARMY RDECOM ARL (US)
> <john.w.raby2.civ at mail.mil>
> Subject: [Non-DoD Source] Re: [rt.rap.ucar.edu #80604] Question
about
> radar reflectivity observations (UNCLASSIFIED)
>
> All active links contained in this email were disabled. Please
verify
> the identity of the sender, and confirm the authenticity of all
links
> contained within the message prior to copying and pasting the
address
> to a Web browser.
>
>
>
>
> ----
>
> Hi John. I see that you are trying to understand the "level" entry
> for the field in the configuration files. While I am certain John
is
> the best person to answer your question, he is out until next week,
so
> I will do what I can to answer your question as best as I can.
>
> In the MET User's Guide for version 6.0:
> Caution-Caution-http://www.dtcenter.org/met/users/docs/users_
> guide/MET_Users_Guide_v6.0.pdf
>
> On page 53, the "level" entry for the "field" entry is described.
> Please refer to that page starting at " File-format specific
settings
> for the "field"
> entry:"
>
> More specifically, I grabbed a random GFS GRIB file and ran "wgrib
-v"
> and grepped for "SPFH" and see the following:
>
> 219:85753384:D=2012040900:SPFH:2 m above gnd:kpds=51,105,2:51hr
> fcst:winds are N/S:"Specific humidity [kg/kg]
>
> In this case you would use level="Z2" to specify the vertical level.
>
> I hope that helps! Please let us know how it goes and if you need
> further assistance.
>
> Thanks,
> Julie
>
>
>
> On Wed, May 24, 2017 at 3:25 PM, Raby, John W USA CIV via RT <
> met_help at ucar.edu> wrote:
>
> >
> > Wed May 24 15:25:55 2017: Request 80604 was acted upon.
> > Transaction: Ticket created by john.w.raby2.civ at mail.mil
> > Queue: met_help
> > Subject: Question about radar reflectivity observations
> (UNCLASSIFIED)
> > Owner: Nobody
> > Requestors: john.w.raby2.civ at mail.mil
> > Status: new
> > Ticket <Caution-Caution-url:
> > Caution-Caution-
https://rt.rap.ucar.edu/rt/Ticket/Display.html?id=80
> > 604 >
> >
> >
> > CLASSIFICATION: UNCLASSIFIED
> >
> > I will be using radar obs to verify modeled radar reflectivity.
The
> > reflectivity obs are in CF-compliant NetCDF format. I'm trying to
> > understand the "level" entry for the field in the config file.
> >
> > An example from the Config file overview text file is on P10 which
> > shows the "name" and "level" entries for the variable called
"QVAPOR".
> > What I would like to do is to be able to explore the model output
> > (GRIB) for the same variable (SPFH) using wgrib -v and use the
grid
> > information in this listing to derive the corresponding "dimension
> > values" which are the equivalent for the QVAPOR observations in
> > NetCDF format. For example:
> >
> > How can I relate the level information for QVAPOR which is
"(0,5,*,*)"
> > to the level information for SPFH as shown by wgrib -v? If this
> > isn't possible and you have to explore the NetCDF file itself,
then
> > maybe you could provide some explanation of the "level" entry so I
> > can pick out from the ncdump of the NetCDF file the info necessary
> > to provide the dimensions in the "level"
> > entry.
> >
> > Using this understanding I hope to determine the correct level
> > dimensions for the radar observations.
> >
> > Thanks.
> >
> > R/
> > John
> >
> > Mr John W. Raby, Meteorologist
> > U.S. Army Research Laboratory
> > White Sands Missile Range, NM 88002
> > (575) 678-2004 DSN 258-2004
> > FAX (575) 678-1230 DSN 258-1230
> > Email: john.w.raby2.civ at mail.mil
> >
> >
> > CLASSIFICATION: UNCLASSIFIED
> >
> >
>
>
> CLASSIFICATION: UNCLASSIFIED
>
>
CLASSIFICATION: UNCLASSIFIED
------------------------------------------------
Subject: Question about radar reflectivity observations (UNCLASSIFIED)
From: Julie Prestopnik
Time: Thu Jun 01 14:59:55 2017
Hi John. I'm glad it helped. Yes, that mapping looks correct to me.
Also,
the "*" tells MET to use all of the values for that dimension.
I'll go ahead and close this ticket for now, but please follow up once
you
have your data if you need help.
Thanks!
Julie
On Thu, Jun 1, 2017 at 1:01 PM, Raby, John W USA CIV via RT <
met_help at ucar.edu> wrote:
>
> <URL: https://rt.rap.ucar.edu/rt/Ticket/Display.html?id=80604 >
>
> CLASSIFICATION: UNCLASSIFIED
>
> Julie -
>
> Thanks for this information. It really helps. I'm seeing that the
info
> contained in the dump of the NetCDF file specifically allows you to
> determine
> the correct level value. This comes from the line in the ncdump
output
> which
> starts with the word "float". I see the string in that line "(time,
> lv_HYBL1,
> y, x)" which appears to correspond with the format for the Grid-Stat
config
> file setting for the level information exactly. So for your example
below
> "(0,44,*,*)" I assume that the following mapping is true:
>
> time = 0
> lv_HYBL44 = 44
> y = * grid field dimension in the y-direction
> x = * grid field dimension in the x-direction
>
> Does the use of "*" act like a wildcard so that it will accept any
grid
> dimensions?
>
> I'll work on gaining access to your ftp site to retrieve the file
you
> placed
> there, but I may have to get an exception to the ftp blocking in
place. I
> tried to find a NetCDF file I could explore to familiarize myself by
> looking
> in the MET (V5.2) install dir. I found one which was produced by the
> pcp-combine tool, but it was generated using MET V4.1 which doesn't
show
> the
> line and the string "(time, lv_HYBL1, y, x)". MY guess is that it
has to
> be a
> CF-compliant NetCDF file to use that string.
>
> R/
> John
>
>
> -----Original Message-----
> From: Julie Prestopnik via RT [mailto:met_help at ucar.edu]
> Sent: Thursday, June 01, 2017 10:25 AM
> To: Raby, John W CIV USARMY RDECOM ARL (US)
<john.w.raby2.civ at mail.mil>
> Subject: Re: [Non-DoD Source] Re: [rt.rap.ucar.edu #80604] Question
about
> radar reflectivity observations (UNCLASSIFIED)
>
> All active links contained in this email were disabled. Please
verify the
> identity of the sender, and confirm the authenticity of all links
contained
> within the message prior to copying and pasting the address to a Web
> browser.
>
>
>
>
> ----
>
> Hi John. I had misunderstood what you were asking, but I think I
better
> understand now.
>
> I put two files on our ftp server (Caution-ftp.rap.ucar.edu) for you
at
> pub/jpresto/for_raby/.
>
> The files are:
>
> 20170601_i12_f002_WRF-RR.grb2
> 20170601_i12_f002_WRF-RR.nc
>
> When I run, "wgrib2 -v 20170601_i12_f002_WRF-RR.grb2 | grep SPFH", I
get
> the
> following for the 3D SPFH var:
>
> 16:637394:d=2017060112:SPFH Specific Humidity [kg/kg]:1 hybrid
level:2 hour
> fcst:
> 35:1709666:d=2017060112:SPFH Specific Humidity [kg/kg]:2 hybrid
level:2
> hour
> fcst:
> 54:2823255:d=2017060112:SPFH Specific Humidity [kg/kg]:3 hybrid
level:2
> hour
> fcst:
> ... (with levels 4 - 47)
> 909:42584590:d=2017060112:SPFH Specific Humidity [kg/kg]:48 hybrid
level:2
> hour fcst:
> 928:43216366:d=2017060112:SPFH Specific Humidity [kg/kg]:49 hybrid
level:2
> hour fcst:
> 947:43826690:d=2017060112:SPFH Specific Humidity [kg/kg]:50 hybrid
level:2
> hour fcst:
>
> This netcdf file has been paired down (only some of the vars) and
put in a
> CF
> compliant format. Likewise, when I run "ncdump -h
> 20170601_i12_f002_WRF-RR.nc
> | grep SPFH", I see the following:
>
> float SPFH_P0_L105_GLC0(time, lv_HYBL1, y, x) ;
> SPFH_P0_L105_GLC0:level_type = "Hybrid level" ;
>
> SPFH_P0_L105_GLC0:parameter_template_discipline_category_number = 0,
0, 1,
> 0 ;
> SPFH_P0_L105_GLC0:parameter_discipline_and_category
=
> "Meteorological products, Moisture" ;
> SPFH_P0_L105_GLC0:grid_mapping = "grid_mapping" ;
> SPFH_P0_L105_GLC0:coordinates = "lat lon" ;
> SPFH_P0_L105_GLC0:_FillValue = 1.e+20f ;
> SPFH_P0_L105_GLC0:units = "kg kg-1" ;
> SPFH_P0_L105_GLC0:long_name = "Specific humidity" ;
> SPFH_P0_L105_GLC0:production_status = "Research
products"
> ;
> SPFH_P0_L105_GLC0:center = "NOAA Forecast Systems
Lab,
> Boulder
> CO" ;-
>
> There is only one time present in this file, so if you wanted to
explore
> the
> 45th hybrid level, I believe you would use "(0,44,*,*)". It would
be "44"
> instead of "45" because of the 0 indexing (starting with 0 as
opposed to
> 1).
>
> I hope this is helpful. Please let me know if you have other
questions.
> Also, once you have your NetCDF file with your radar obs, let us
know if we
> can help with your specific situation.
>
> Thanks,
> Julie
>
>
>
> On Wed, May 31, 2017 at 3:17 PM, Raby, John W USA CIV via RT <
> met_help at ucar.edu> wrote:
>
> >
> > <Caution-url:
> > Caution-https://rt.rap.ucar.edu/rt/Ticket/Display.html?id=80604 >
> >
> > CLASSIFICATION: UNCLASSIFIED
> >
> > Hi Julie -
> >
> > Thanks for addressing my question.
> >
> > I looked at p.53 and it describes the level entry if you were
using
> > GRIB formatted files. In the case of the radar observations, the
> > format will be NetCDF (CF-compliant). I looked at p.54 where it
does
> > talk about those entries which are notably different from those
used
> > for GRIB files. I cited the example shown on this page (54) for
the
> > variable "QVAPOR" in my email below thinking that SPFH which is
> > present in a GRIB file would be analogous to QVAPOR and thus might
be
> > an easy way to determine the "level" values (Z2 for
> > GRIB) and then convert it to the equivalent "level" entry for a
NetCDF
> > file.
> > I'm also a little confused about the other part of the "level"
entry
> > for NetCDF which is called "dimensions". Using wgrib -v or some
other
> > option one should be able to determine what the "dimension" is as
well
> > as the level.
> > At
> > least, that's what I think and I am no expert on this. It may be
that
> > this information can't be determined by exploring the GRIB file
> > equivalent of QVAPOR and you must explore the NetCDF file instead
to
> find it
> > out.
> > Unfortunately, I don't have a NetCDF file for my radar obs yet, so
I
> > can't explore them yet, but there must be other NetCDF output
which
> > could be used.
> > An example could be the output of the Pcp_Combine tool which is a
> > gridded NetCDF file which is input into Grid-Stat for either the
> > observation file or the fcst file or both. The same "level" entry
> > would have to be specified in the Grid-Stat config file in order
for
> > it to read the NetCDF input files.
> >
> > This can certainly wait until next week when John gets back on
this,
> > so don't go to great lengths to provide an answer now.
> >
> > R/
> > John
> >
> > -----Original Message-----
> > From: Julie Prestopnik via RT [Caution-mailto:met_help at ucar.edu]
> > Sent: Wednesday, May 31, 2017 2:45 PM
> > To: Raby, John W CIV USARMY RDECOM ARL (US)
> > <john.w.raby2.civ at mail.mil>
> > Subject: [Non-DoD Source] Re: [rt.rap.ucar.edu #80604] Question
about
> > radar reflectivity observations (UNCLASSIFIED)
> >
> > All active links contained in this email were disabled. Please
verify
> > the identity of the sender, and confirm the authenticity of all
links
> > contained within the message prior to copying and pasting the
address
> > to a Web browser.
> >
> >
> >
> >
> > ----
> >
> > Hi John. I see that you are trying to understand the "level"
entry
> > for the field in the configuration files. While I am certain John
is
> > the best person to answer your question, he is out until next
week, so
> > I will do what I can to answer your question as best as I can.
> >
> > In the MET User's Guide for version 6.0:
> > Caution-Caution-http://www.dtcenter.org/met/users/docs/users_
> > guide/MET_Users_Guide_v6.0.pdf
> >
> > On page 53, the "level" entry for the "field" entry is described.
> > Please refer to that page starting at " File-format specific
settings
> > for the "field"
> > entry:"
> >
> > More specifically, I grabbed a random GFS GRIB file and ran "wgrib
-v"
> > and grepped for "SPFH" and see the following:
> >
> > 219:85753384:D=2012040900:SPFH:2 m above gnd:kpds=51,105,2:51hr
> > fcst:winds are N/S:"Specific humidity [kg/kg]
> >
> > In this case you would use level="Z2" to specify the vertical
level.
> >
> > I hope that helps! Please let us know how it goes and if you need
> > further assistance.
> >
> > Thanks,
> > Julie
> >
> >
> >
> > On Wed, May 24, 2017 at 3:25 PM, Raby, John W USA CIV via RT <
> > met_help at ucar.edu> wrote:
> >
> > >
> > > Wed May 24 15:25:55 2017: Request 80604 was acted upon.
> > > Transaction: Ticket created by john.w.raby2.civ at mail.mil
> > > Queue: met_help
> > > Subject: Question about radar reflectivity observations
> > (UNCLASSIFIED)
> > > Owner: Nobody
> > > Requestors: john.w.raby2.civ at mail.mil
> > > Status: new
> > > Ticket <Caution-Caution-url:
> > > Caution-Caution-
https://rt.rap.ucar.edu/rt/Ticket/Display.html?id=80
> > > 604 >
> > >
> > >
> > > CLASSIFICATION: UNCLASSIFIED
> > >
> > > I will be using radar obs to verify modeled radar reflectivity.
The
> > > reflectivity obs are in CF-compliant NetCDF format. I'm trying
to
> > > understand the "level" entry for the field in the config file.
> > >
> > > An example from the Config file overview text file is on P10
which
> > > shows the "name" and "level" entries for the variable called
"QVAPOR".
> > > What I would like to do is to be able to explore the model
output
> > > (GRIB) for the same variable (SPFH) using wgrib -v and use the
grid
> > > information in this listing to derive the corresponding
"dimension
> > > values" which are the equivalent for the QVAPOR observations in
> > > NetCDF format. For example:
> > >
> > > How can I relate the level information for QVAPOR which is
"(0,5,*,*)"
> > > to the level information for SPFH as shown by wgrib -v? If this
> > > isn't possible and you have to explore the NetCDF file itself,
then
> > > maybe you could provide some explanation of the "level" entry so
I
> > > can pick out from the ncdump of the NetCDF file the info
necessary
> > > to provide the dimensions in the "level"
> > > entry.
> > >
> > > Using this understanding I hope to determine the correct level
> > > dimensions for the radar observations.
> > >
> > > Thanks.
> > >
> > > R/
> > > John
> > >
> > > Mr John W. Raby, Meteorologist
> > > U.S. Army Research Laboratory
> > > White Sands Missile Range, NM 88002
> > > (575) 678-2004 DSN 258-2004
> > > FAX (575) 678-1230 DSN 258-1230
> > > Email: john.w.raby2.civ at mail.mil
> > >
> > >
> > > CLASSIFICATION: UNCLASSIFIED
> > >
> > >
> >
> >
> > CLASSIFICATION: UNCLASSIFIED
> >
> >
>
>
> CLASSIFICATION: UNCLASSIFIED
>
>
------------------------------------------------
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