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[GEMPAK #CMJ-289235]: GEMPAK synop decoder



> Hello Steve,
> 
> 
> I've found that we have a regional practice (Region III) in wich synop
> precipitation group is always 24 hours accumulated. Hence at 12Z,
> GEMPAK  decoder should assume 0.00 for P24M instead of P06M for Region
> III only.  Is it possible?

Giovanni,

The $GEMPAK/source/bridge/ls/lsprec.f routine could be modified for
region 3 specific cases. At the moment, it sets p03m or p06m to 0.
depending on the mod(hour) of observation and returns. An
extra check on the kwmo common variable for region 3 could be
addded to set p24m to 0. as well. I had posted the 5.10.4 distribution
Monday, but could back this change in. Or, do you want the source code 
change to update the ldprec.f routine in your current
distribution? I've attached this routine. You can replace your
$GEMPAK/source/bridge/ls/lsprec.f and then:

cd $GEMPAK/source/bridge/ls
make all
ar rv $GEMLIB/bridge.a *.o
make clean

cd $GEMPAK/source/programs/dclsfc
make clean all install clean

Steve Chiswell
Unidata User Support




> 
> Cheers
> 
> On Mon, 2007-10-15 at 10:44 -0600, Unidata GEMPAK Support wrote:
> > Giovanni,
> >
> > The dclsfc decoder checks the i(r) indicator, and if it is a 3, it
> > assumes that P06M is 0.00:
> > -- rsdeco.f
> > C
> > C*      If no rain observed, assume six hour dry period
> > C
> >
> > The decoder does not assume a dry period of 0.00" for any other
> > time interval- that time interval would be given by the t(r) in
> > the 6RRRt(r) group.
> >
> > The SFLIST=dset will show the following periods in the default packing file:
> >
> > P03M;P06M;P09M;P12M;P18M;P24M
> >
> > Only the P06M will be 0.00 if the 6RRRt(r) group is ommitted. The rest are
> > filled with -9999.00. That is, the P24M parameter will only be defined
> > when t(r) is "4" as in 60004.
> >
> > I do see synoptic obs with 60004 encoded, but don't know if it is legal
> > to have i(r) = 3 if there has been any observed precip in the previous
> > 24 hours, but not in the most recent 6 hours- but the decoder does
> > not make that assumption.
> >
> > Steve Chiswell
> > Unidata User Support
> >
> >
> >
> > > Hello Steve,
> > >
> > > I have one doubt about how exactly the "dclsfc" GEMPAK decoder
> > > interpret
> > > the synop message 111 Group precipitation indicator. I realized that
> > > when the precipitation indicator indicates that "
> > > 3 -- Precipitation omitted, no precipitation" the dclsfc decodes it as a
> > > missing information (-9999.00) what does not seem to be apropriate. The
> > > correct decodification should be "0.00". I believe that the missing
> > > value -9999.00 should be used only when the "111 Group precipitation
> > > indicator" is reporting "4 -- Precipitation omitted, no observation"
> > > Two examples are shown below:
> > >
> > >
> > > ### In Brazil
> > >
> > > 111200 83997 32597 51408 10160 20129 30171 40216 51017 82201 333 20121
> > >
> > > STN    YYMMDD/HHMM      STID     TMPC     P24M
> > > 839970    071011/1200              16.00 -9999.00
> > >
> > >
> > > ### In USA
> > >
> > > 111200 72797 35966 60806 10094 20072 30121 40184 56005 91153 333 10161
> > > 555 91112
> > >
> > > STN    YYMMDD/HHMM      STID     TMPC     P24M
> > > 727970    071011/1200       UIL     9.40 -9999.00
> > >
> > >
> > >
> > > This interpretation of synop messages is causing a lot of data losses.
> > >
> > > Cheers
> > >
> > >
> > >
> > > --
> > > Giovanni Dolif
> > > Meteorologist, Msc. and Ph.D. Student
> > > National Institute for Space Research (INPE)
> > > Weather Forecast and Climate Studies Center (CPTEC)
> > > km 40, Rod. Pres. Dutra
> > > 12630-000, Cachoeira Paulista, SP, Brazil
> > > Phone: +55 (12) 3186-8400
> > > FAX:   +55 (12) 3101-2835
> > > http://www.inpe.br/ingles/index.php
> > > http://www.cptec.inpe.br/
> > >
> > >
> >
> >
> > Ticket Details
> > ===================
> > Ticket ID: CMJ-289235
> > Department: Support GEMPAK
> > Priority: Normal
> > Status: Closed
> >
> --
> Giovanni Dolif
> Meteorologist, Msc. and Ph.D. Student
> National Institute for Space Research (INPE)
> Weather Forecast and Climate Studies Center (CPTEC)
> km 40, Rod. Pres. Dutra
> 12630-000, Cachoeira Paulista, SP, Brazil
> Phone: +55 (12) 3186-8400
> FAX:   +55 (12) 3101-2835
> http://www.inpe.br/ingles/index.php
> http://www.cptec.inpe.br/
> 
> 


Ticket Details
===================
Ticket ID: CMJ-289235
Department: Support GEMPAK
Priority: Normal
Status: Closed

Attachment: lsprec.f
Description: Binary data