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20041220: 20041216: GFS pqact entries



Ken,

To just request the GFS 700mb pressure level grid #211 data,
the easiest solution is to key on the WMO identifier
fields which follow the conventions documented at:

http://www.nco.ncep.noaa.gov/pmb/docs/on388/appendixa.html

The WMO headers follow the form TTAAii KWB.
for the 700 mb level, the "ii" field would be "70",
so you could request:

HDS     ^[YZ].Q.70 KWBC

The "KWBC" is the GFS model designator for AWIPS grid identifiers
beginning with [YZ].

The KWBC identifier is not unique to GFS when matching on 
grids beginning with "H" which would be the thinned tiles,
so in that case I would add the .*/m(AVN|GFS|SSIAVN|SSIGFS)
string following KWBC.

In general, you will find that changes to NWS datastream contents
make using old decoders problematic. But, decoding grid #211 GFS 
with dcgrib is possible with the current data stream contents; 
However, the GEMPAK 5.4 tables cannot be guaranteed to be up to 
date with respect to parameters etc. added to the data stream over 
time. You might find some log messages about missing parameters etc. 
in old tables.  The use of dcgrib and/or GEMPAK 5.4 instead of 
dcgrib2 and a current version is likely to be brittle in keeping 
pace with data stream changes.

Steve Chiswell
Unidata User Support

>From: Ken Scheeringa <address@hidden>
>Organization: UCAR/Unidata
>Keywords: 200412201945.iBKJjWlI009529

>On Fri, 17 Dec 2004, Unidata Support wrote:
>
>Hi support,
>
>A followup question to your last reply (quoted below):
>
>
>For example let's say I only want the 700 mb GFS forecasts.
>In my pqact pattern, would I add a clause that begins with
>
>!grib/ncep/GFS/#211/   etc etc  etc   /700 mb/
>
>at the end of an HDS pattern that starts with
>
>HDS      ^[YZ].Q... KWB.         etc etc
>
>to isolate the 700 mb grid, or is this even possible?
>Or is it the job of 'dcgrib2' to split out this pressure level?
>
>
>Since I am only after a single grid #211, MUST I use dcgrib2
>to extract the data?  I am running GEMPAK 5.4 which has
>dcgrib but not dcgrib2.  I am not stitching octets together
>so I wonder if dcgrib will do the job just as well?
>
>If I must use dcgrib2, then could I download just the binary
>for that program and run it, or does dcgrib2 depend on other
>modules/settings resident in the GEMPAK 5.7 version?  As you
>can see, I am hunting down the most direct route possible to get at
>the contents of the grids.  Our goal is to import a (hopefully)
>text version of the grid contents into an independant
>trajectory model.
>
>I have used CPC software before that converts their upper air
>reanalysis grids from netCDF into text output for use in an
>independant model.  I don't know if something like that is
>available for GRIB2 conversion as well.
>
>Your advice is very welcome here!
>
>
>> Ken,.
>> 
>> I provide the following pattern examples for GEMPAK:
>> 
>> #
>> # NOAAport GFS/AVN model output
>> # -----------------------
>> # AWIPS grids
>> # Grid #201 N. Hemisphere 381km: ^[YZ].A... KWBC.*/m(AVN|SSIAVN|GFS|SSIGFS)
>> # Grid #202 CONUS         190km: ^[YZ].I... KWBC.*/m(AVN|SSIAVN|GFS|SSIGFS)
>> # Grid #203 Alaska        190km: ^[YZ].J... KWBC.*/m(AVN|SSIAVN|GFS|SSIGFS)
>> # Grid #211 CONUS          80km: ^[YZ].Q... KWBC.*/m(AVN|SSIAVN|GFS|SSIGFS)
>> # Grid #213 CONUS          95km: ^[YZ].H... KWBC.*/m(AVN|SSIAVN|GFS|SSIGFS)
>> # Grid #225 Hawaii         80km: ^[YZ].G... KWBC.*/m(AVN|SSIAVN|GFS|SSIGFS)
>> #
>> # Select any/all grids desired from [AGHIJQ]
>> HDS     ^[YZ].[AGHIJQ]... KWB. ([0-3][0-9])([0-2][0-9]).*/m(AVN|SSIAVN|GFS|S
> SIGFS)
>>         PIPE    decoders/dcgrib2 -d data/gempak/logs/dcgrib2_GFS.log
>> #
>> # Global GFS (Spectral) Thinned grids
>> # Grid octets I-P will be stitched together as a single global grid
>> #
>> HDS     ^H.[I-P]... KWBC ([0-3][0-9])([0-2][0-9])
>>         PIPE    decoders/dcgrib2 -d data/gempak/logs/dcgrib2_GFSthin.log
>> 
>> 
>> You would most likely be interested in the #211 grid (grid identified "Q")
>> in the first pattern shown above.
>> 
>> Steve Chiswell
>> Unidata User Support
>> 
>> 
>> 
>> 
>> >From: Ken Scheeringa <address@hidden>
>> >Organization: UCAR/Unidata
>> >Keywords: 200412162005.iBGK52lI008602
>> 
>> >
>> >Hello again support,
>> >
>> >Can you give me some examples of pqact.conf entries
>> >that use the HDS feed to capture GFS grids for
>> >specific levels and parameters for the CONUS?
>> >I have been looking for some on the web but haven't
>> >found it yet.
>> >
>> >Thanks!
>> >
>> >
>> >On Fri, 10 Dec 2004, Unidata Support wrote:
> >
>> >> 
>> >> Ken,
>> >> 
>> >> The CONDUIT grids for GFS are all global grids, so you wouldn't be
>> >> able to restrict the incoming data to just CONUS. You could restrict to
>> >> specific parameters, levels, etc depending on feedtype, but the grid is
>> >> a single size...and the CONDUIT grids are large. Depending on your input
>> >> data need, you could restrict the incoming grids to certain forecast time
> s,
>> >> but if you don't need the full set of levels and parameters, you may
>> >> want to use the data available via the HDS data stream.
>> >> 
>> >> There are CONUS GFS grids in the HDS data stream of the IDD.
>> >> These would be the #211 grid which is 80km. These are at the same 
>> >> covereage and resolution as the ETA (aka NAM) and RUC grids available
>> >> on grid #211.
>> >> 
>> >> Steve Chiswell
>> >> Unidata User SUpport
>> >> 
>> >> 
>> >> 
>> >> >From: Ken Scheeringa <address@hidden>
>> >> >Organization: UCAR/Unidata
>> >> >Keywords: 200412101855.iBAItYlI003044
>> >> 
>> >> >Hello,
>> >> >
>> >> >I am exploring the use of the GFS model grids as a data
>> >> >source for near-term projection of the transport of soybean
>> >> >rust spores from the US Gulf Coast states next year into Indiana.
>> >> >(Soybean rust is a dreaded soybean disease new to the USA.)
>> >> >
>> >> >I am unsure about how to set up a pqact.conf entry to limit
>> >> >the forecast grids to just the continental USA.  I don't want
>> >> >to overwhelm our aged UNIX machine with data outside our
>> >> >geographical area of interest.
>> >> >
>> >> >I have read your online "IDD feed naming conventions" segment
>> >> >as well as your recent emails on the subject.  Some of the
>> >> >examples begin with:
>> >> >
>> >> >CONDUIT /afs/.nwstg.nws.noaa.gov/ftp/SL.us008001......!grib/ncep/....
>> >> >
>> >> >and others just have
>> >> >CONDUIT MT.gfs....
>> >> >
>> >> >while I also find
>> >> >HDS | CONDUIT......
>> >> >
>> >> >
>> >> >An alternative to LDM might be to download the model output
>> >> >from the NWS 'tgftp' web site, but I don't see any options there
>> >> >to narrow selections down to the   !grib/ncep/96/#003/.....00016 
>> >> >type of criteria.
>> >> >
>> >> >It may be I just don't understand these various request formats
>> >> >and grid number assignments.  Or maybe I should be using a
>> >> >different forecast model?
>> >> >
>> >> >Given my objective stated at the beginning, can you recommend
>> >> >how I can obtain just the data I really need and perhaps which
>> >> >access method would be the most efficient?
>> >> >
>> >> >Thanks!
>> >> >
>> >> >
>> >> >************************************************************************
> ***
>> > ***
>> >> > *
>> >> >Ken Scheeringa                       Indiana Climate Page
>> >> >State Climatologist                  http://shadow.agry.purdue.edu
>> >> >Agronomy Dept                          
>> >> >Purdue University                      featuring climate data archives:
>> >> >e-mail: address@hidden                  daily coop stations :     1994+
>> >> >fax: 765.496.2926                        hourly airport data : Jul 1996+
>> >> >phone: 765.494.8105                      30-min autostation  :     1999+
>> >> >                                       updated daily
>> >> >                                         Also monthly/daily normals 
>> >> >************************************************************************
> ***
>> > ***
>> >> > *
>> >> >
>> >> --
>> >> *************************************************************************
> ***
>> >> Unidata User Support                                    UCAR Unidata Prog
> ram
>> >> (303)497-8643                                                  P.O. Box 3
> 000
>> >> address@hidden                                   Boulder, CO 80
> 307
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>> >
>> >***************************************************************************
> ***
>> > *
>> >Ken Scheeringa                       Indiana Climate Page
>> >State Climatologist                  http://shadow.agry.purdue.edu
>> >Agronomy Dept                          
>> >Purdue University                      featuring climate data archives:
>> >e-mail: address@hidden                  daily coop stations :     1994+
>> >fax: 765.496.2926                        hourly airport data : Jul 1996+
>> >phone: 765.494.8105                      30-min autostation  :     1999+
>> >                                       updated daily
>> >                                         Also monthly/daily normals 
>> >***************************************************************************
> ***
>> > *
>> >
>> --
>> ****************************************************************************
>> Unidata User Support                                    UCAR Unidata Program
>> (303)497-8643                                                  P.O. Box 3000
>> address@hidden                                   Boulder, CO 80307
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>
>******************************************************************************
> *
>Ken Scheeringa                       Indiana Climate Page
>State Climatologist                  http://shadow.agry.purdue.edu
>Agronomy Dept                          
>Purdue University                      featuring climate data archives:
>e-mail: address@hidden                  daily coop stations :     1994+
>fax: 765.496.2926                        hourly airport data : Jul 1996+
>phone: 765.494.8105                      30-min autostation  :     1999+
>                                       updated daily
>                                         Also monthly/daily normals 
>******************************************************************************
> *
>
>
--
NOTE: All email exchanges with Unidata User Support are recorded in the
Unidata inquiry tracking system and then made publicly available
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available in this way, you must let us know in each email you send to us.