Users of Unidata IDD CONDUIT feed products,
This coming Wednesday, March 17, the IDD CONDUIT feed will be enhanced
by the replacement of GFS v15.3 model output with GFS v16 model output.
In addition to the change in GFS version data, additional vertical
levels, increased grid precision, and the addition of new variables
will _significantly_ increase the volume of data flowing in CONDUIT
especially during the 6-hourly volume peak periods. A test feed from
NCEP to Unidata showed that there can/will be up to 20GB more data
available during the 6-hourly peaks, and this increased volume will
have implications on product residency times in the LDM queues for sites
receiving the full CONDUIT feed or the full GFS portion of the CONDUIT
feed, so local LDM queue sizes may need to be increased.
A breakdown of each dataset that will be impacted is shown in the
following provided by NCEP for data from a GFS/GDAS 12Z cycle where PROD =
v15.3 and PARA = v16:
gfs.t12z.pgrb2.0p25.f* - PROD: 30 GB, PARA: 47 GB -> difference + 17GB/cycle
gfs.t12z.pgrb2.0p50.f* - PROD: 13 GB, PARA 20 GB -> difference + 7GB/cycle
gfs.t12z.pgrb2.1p00.f* - PROD: 3.6 GB, PARA: 5.5 GB -> difference + 2GB/cycle
gdas.t12z.pgrb2.1p00.anl - PROD: 22MB, PARA: 35 MB -> difference + 13MB/cycle
The changes in GFS v16 are described in Section 3 of the following NOAA
Service Change Notice (SCN):
Service Change Notice 21-20
https://www.weather.gov/media/notification/scn_21-20_gfsv16.0_aaa_update.pdf
Section 6 of this SCN describes changes in product size and delivery
stating that pgrb2 files will see a 55% increase in size with the GFS
v16 upgrade.
We apologize for the late notice of the impending changes, but we have
been struggling to get a test feed of the reconstituted datastream for
some time, and the success of the test has been sporadic, so it was
difficult to fully understand the impact that will be experienced with
the data volume increase.
Please send questions/comments to:
Unidata User Support <support@xxxxxxxxxxxxxxxx>
Best regards,
Unidata User Support
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