[Met_help] [rt.rap.ucar.edu #79670] History for Grib2 PRMSL Level

[John Halley Gotway via RT]

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  Initial Request
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John, what is the correct level designator for GRIB2 PRMSL.  I tried Z0, L0, P0 but none work.  In the grib2 file, the PRMSL level is 'mean sea level'.  

Thanks



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  Complete Ticket History
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Subject: Grib2 PRMSL Level
From: John Halley Gotway
Time: Tue Feb 28 16:00:38 2017

Bob,

I see you're having trouble selecting the PRMSL record from a GRIB2
file.
The devil, of course, is in the details, in just exactly how the level
information is encoded for that record.

But for testing, I did the following...

# Pull a recent GFS file:
wget http://www.ftp.ncep.noaa.gov/data/nccf/com/gfs/prod/gfs.
2017022812/gfs.t12z.pgrb2.0p25.f006

# Use wgrib2 to find PRMSL (it's in record number 414)
wgrib2 gfs.t12z.pgrb2.0p25.f006 | grep PRMSL
414:234612707:d=2017022812 <%28201%29%20702-2812>:PRMSL:mean sea
level:6
hour fcst:

# Run MET's plot_data_plane tool to try to grab that data and plot it
met-5.2/bin/plot_data_plane gfs.t12z.pgrb2.0p25.f006 prmsl.ps
'name="PRMSL"; level="L0";' -v 3

DEBUG 1: Opening data file: gfs.t12z.pgrb2.0p25.f006
DEBUG 3: Switching the GRIB2 radius of the earth value of 6371.23 km
to
6371.2 km for internal consistency.
DEBUG 3: MetGrib2DataFile::data_plane() - Found exact match for
'PRMSL/L0'
in GRIB2 record 414 field 1 of GRIB2 file 'gfs.t12z.pgrb2.0p25.f006'
DEBUG 1: Creating postscript file: prmsl.ps

MET version 5.2 correctly finds PRMSL in record 414 and the resulting
image
is attached.  Using either "L0" or "Z0" worked for me.

So why did it work for me and not for you?

I tried running with earlier versions of the code:
- Version 5.2 as originally released works for L0 and Z0.
- Version 5.1 works for L0 and Z0.
- Version 5.0 works for L0 but not for Z0.
- Version 4.1 works for L0 but not for Z0.

I looked through the met_help history and guess that this may be
related to
this question from Matt Sittel:
   http://mailman.ucar.edu/pipermail/met_help/2016-August/002638.html

Please read through that message history.  Looks like it *should* have
been
fixed in version 5.2 of MET.  If that's not the case, please let me
know.

Thanks,
John


On Tue, Feb 28, 2017 at 1:16 PM, robert.craig.2 at us.af.mil via RT <
met_help at ucar.edu> wrote:

>
> Tue Feb 28 13:16:11 2017: Request 79670 was acted upon.
> Transaction: Ticket created by robert.craig.2 at us.af.mil
>        Queue: met_help
>      Subject: Grib2 PRMSL Level
>        Owner: Nobody
>   Requestors: robert.craig.2 at us.af.mil
>       Status: new
>  Ticket <URL:
https://rt.rap.ucar.edu/rt/Ticket/Display.html?id=79670 >
>
>
> John, what is the correct level designator for GRIB2 PRMSL.  I tried
Z0,
> L0, P0 but none work.  In the grib2 file, the PRMSL level is 'mean
sea
> level'.
>
> Thanks
>
>
>

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