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20011128: GEMPAK: SYNOP and WNUM

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  • Subject: 20011128: GEMPAK: SYNOP and WNUM
  • Date: Wed, 28 Nov 2001 14:56:21 -0700
>From: Christian Page <address@hidden>
>Organization: UCAR/Unidata
>Keywords: 200111281609.fASG9QN17626

>
>Hi,
>
>I would like to use SFPARM=WNUM for both METAR and SYNOP data in SFLIST.
>Currently I use WSYM, but I found it less precise than WNUM.
>But it seems that WNUM is not available in SYNOP data, am I right?
>Is it possible to get it just by adding WNUM in the packing file for SYNOP?
>
>Thanks,
>
>Christian Page
>UQAM
>
>

Christian,

The WMO weather codes reported by synoptic observations are stored
by the dclsfc decoder using the WWMO and PWWM parameters. These
are the exact codes that correspond to the WMO code tables 4677 and 4680
for present weather, and 4531 and 4561 for past weather. Only the
types of phenomena in the tables can be coded into a synoptic
observation, so the number of types is more limited than the metar
observation.

WWMO can be expressed in the weather types using WTHR in sflist.
The WSYM number is a conversion of WNUM in the metar observation to
the closest code table number available.

If you want to have the exact output of the synoptic observation, then
WWMO is that variable for present weather.

Steve Chiswell
Unidata User Support