NOAA / NWS's Meteorological Development Laboratory
Degrib (NDFD GRIB2 Decoder)
Subject: Degrib 1.79
Date: Mon, 22 May 2006 11:15:14 -0400
To: Arthur Taylor
You have the unique distinction of being registered on the degrib
mailing list (all 1120 of us). Please email me if you want to
unregister. The latest version of the program is on:
www.weather.gov/mdl/degrib/ or www.weather.gov/mdl/NDFD_GRIB2Decoder/.
----------- General News:
TIN06-30: (http://www.nws.noaa.gov/om/notif.htm) was sent out around
5/9/2006, informing us that on 9/6/2006 NDFD element files will be split
into 2 files. One for "days 1 to 3", and the other for "days 4 to 7".
The plan is to update the "days 4 to 7 file" 4 times a day, while
updating the "days 1 to 3 file" hourly. To do this, NDFD will need to
add a directory to the URL's, and change the WMO headers. More info
(via a TIN) has been promised by June 1, 2006.
What does this mean for Degrib? When tcldegrib or tkdegrib download
gridded MOS data to the local machine, they create
"data/ndgd/gfsmos/conus/maxt_d47.bin". The current thought is to mimic
this for the NDFD creating "data/ndfd/conus/maxt_d13.bin".
The alternative would be to merge the files, which could be useful for
people used to working with a single file. One problem with this would
be determining if one needed to download the "d47" file, since it is
only updated every 6 hours. This is not insurmountable since the GRIB
messages have a reference time. I'd welcome any discussion as to how
this will affect you, and your preference.
Thanks to Jodie Towers and Doug Marcy (at NOAA's Coastal Service
Center) we now have two new tutorials for degrib:
A) "NDFD Tkdegrib Tutorial" at:
B) "Using NDFD gridded data in a GIS Environment" at:
If you have any comments send them to email@example.com and
TIN06-24: was sent out around 5/2/2006, informing us that the Real
Time Mesoscale Analysis grids will be added to the NDGD on 8/1/2006.
They are going to start with "temperature (and error)" "dewpoint (and
error)" "u-wind (and error)" "v-wind (and error)" "precipitation", and
"GOES effective cloud amount". They are planning to add "wind speed"
and "wind direction" late in 2006. If you have comments, send them to
tkdegrib/tcldegrib should be able to simply add a new entry in their
configuration files for the new data. The main issue will be that the
u-wind and v-wind are likely to be in separate files making it difficult
to recover wind speed and wind direction.
----------- News about this release:
I have just finished putting together version "1.79" (last one that I
announced was "1.77" on 3/15/2006).
This release focused primarily on 2 things, providing degrib with DWML
generating capability, and "psurge" support.
1) DWML generation: Thanks to Paul Hershberg, and John Schattel, degrib
can now generate DWML. This should allow people, who are users of the
DWML web service, to switch to downloading the GRIB files, and creating
DWML output on their machines. The advantage of this is that it will
allow DWML users to probe multiple points faster, and get faster turn
around for single points since the ASCII XML doesn't have to traverse
the net. In addition it will alleviate the pressure on the NWS's DWML
web service machines. For more info on "DWML" see:
For more info on how to use this new feature, see:
1b) To support this effort, I added libxml to the distribution code.
2) "psurge" support: To encode some of the psurge products in GRIB2
required using template 4.10. Unfortunately degrib did not support 4.10
(until now), and psurge needed that support by the beginning of
hurricane season (6/1/2006).
If you're wondering what "psurge" is, it stands for "probabilistic
hurricane storm surge", and is my "primary project". A Public
Information Statement was sent out on 5/5/2006 requesting comments. (see
The web site for psurge is "http://www.nws.noaa.gov/mdl/psurge", and I'd
appreciate any comments you have.
3) Thanks goes to Jack Wasey for helping with the pure cygwin makefiles
4) Updated packages so all copies have geodata (timezone / daylight files).
5) Finished adding "engribapi.c" to grib2lib. Hope to use this to give
degrib better encoding support in the future.
6) Found a bug when setting the tangent latitude for polar stereographic
and mercator TDLPack grids.
Please let me know if you have problems.