Re: [ldm-users] Grib data in the IDS|DDPLUS feed

Daryl,

Fascinating, Discipline 78 isn't an official discipline as defined in any
grib2 tables, so no wonder wgrib2 spits that out.

KWBN is indeed the NDFD source as you noted, but center 7 is NCEP, center 8
is NDFD...

If I look at current grib2 tables and ignore the discipline, here are what
seem like top candidates matching your other values:

NCEP:
https://github.com/NOAA-EMC/wgrib2/blob/7bce4ba3baf96c85fb05a334c3ea8fbe01b41367/wgrib2/gribtables/ncep/gribtable.dat
{0,0,0,255,7,1,1,192, "CRAIN", "Categorical Rain", "-"},
{1,0,0,255,7,1,1,192, "CPOZP", "Probability of Freezing Precipitation",
"%"},
{2,0,0,255,7,1,1,192, "CANL", "Cold Advisory for Newborn Livestock", "-"},
{3,0,0,255,7,1,1,192, "USCT", "Scatterometer Estimated U Wind Component",
"m/s"},
{10,0,0,255,7,1,1,192, "OMLU", "Ocean Mixed Layer U Velocity", "m/s"},

NDFD:
https://github.com/NOAA-EMC/wgrib2/blob/7bce4ba3baf96c85fb05a334c3ea8fbe01b41367/wgrib2/gribtables/ndfd/NDFD_gribtable.dat
{0,1,0,255,8,1,1,192, "WX", "Weather information", "WxInfo"},

Between that and the non-standard L..... product code, I think you're right
if the timing aligns with that PNS your example is closest to a "Ocean
Mixed Layer U Velocity" variable in a provisional/exper status.  While that
"mixed layer" isn't listed in that PNS, discipline 10 such as that product
would be an oceanographic product if it were in prod.  I've set up a pqact
to capture new products and I'll take another look when more come in.

Opinion:  IF I'm close to right on this, my two cents are it'd merit a
message to those contact points as I don't think them landing in IDS|DDPLUS
is intentional.  HDS I'd buy, but not here.  Although, with Can. Radar
persisting in this feedtype too would two data points make a trend?  If so
there could be a larger issue looming...

Thanks for the head-scratcher, this is worth keeping an eye on.

-Mike

On Thu, Jan 22, 2026 at 10:12 AM Herzmann, Daryl E [AGRON] <
akrherz@xxxxxxxxxxx> wrote:

> Hi Mike,
>
> Thanks for the response and interest.  The WMO source is KWBN, which is
> the NDFD.  My guess is that the products are related to this:
>
>
> https://www.weather.gov/media/notification/pdf_2025/pns25-81_Experimental_OPC_High_Seas_Gridded_Fcsts_NDFD.pdf
>
> wgrib2 isn't very helpful as my grib tables must be old.  An example:
>
> 1:28:d=2026012112:var discipline=78 center=7 local_table=1 parmcat=1
> parm=192:surface - surface:69 hour fcst:
>
> daryl
>
> ________________________________________
> From: Mike Zuranski <mike@xxxxxxxxxxxxxxxxxxx>
> Sent: Wednesday, January 21, 2026 4:27 PM
> To: Herzmann, Daryl E [AGRON]
> Cc: LDM
> Subject: Re: [ldm-users] Grib data in the IDS|DDPLUS feed
>
> Hey Daryl,
>
> I have to ask, did you bother to peak at the data to see what it actually
> is?  My hunch is model output but L products are strangely omitted from the
> following table:  https://www.weather.gov/tg/tablea  So now I'm curious.
>
> -Mike
>
>
> On Wed, Jan 21, 2026 at 3:48 PM Herzmann, Daryl E [AGRON] <
> akrherz@xxxxxxxxxxx<mailto:akrherz@xxxxxxxxxxx>> wrote:
> Greetings,
>
> I was reviewing my IDS|DDPLUS archival and noticed that my hourly files
> have a large variance in size.
>
>  26M 2026012104.txt
> 390M 2026012105.txt
>  27M 2026012106.txt
> ...snipped...
>  30M 2026012116.txt
> 387M 2026012117.txt
>  27M 2026012118.txt
>
> So I had a look at my LDM telemetry logging and see the the following byte
> counts for IDS|DDPLUS for the 17 UTC hour today
>
>  wmo_ttaaii |    sum
> ------------+------------
>  SDCN01     | 1700051333
>  LDUD00     |   34844596
>  LDUD06     |   34771861
>  LDUD12     |   34731012
>  LDUE00     |   34702011
>  LDUD18     |   34668540
>  LDUE06     |   34664366
>  LDUE12     |   34593737
>  LDUH12     |   34560734
>  LDUE18     |   34527322
>  LDUH06     |   34485257
>  LDUF06     |   34466943
>  LDUF00     |   34458010
>  LDUF12     |   34452545
>  LDUF18     |   34412543
>  LDUH00     |   34405475
>  LDUG18     |   34382563
>  LDUG00     |   34381983
>  LDUG06     |   34376450
>  LDUG12     |   34366267
>  LDUH18     |   16845611
>
>
> Of course, the Canadian RADAR (SDCN01) is well known fun that I was
> already excluding from the file write, but what is LDUD00? Well, it is grib
> data:
>
> LDUD00 KWBN 211200
> GRIB^@^@^A^B...
>
> So folks may wish to update their pqact's to exclude these as well!
>
> daryl
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