NOAA / NWS's Meteorological Development Laboratory
Degrib (NDFD GRIB2 Decoder)
Subject: Degrib 1.53
Date: Mon, 21 Jun 2004 11:52:25 -0400
From: Arthur Taylor
You all have the unique distinction of being registered on my degrib
(aka NDFD_GRIB2Decoder) mailing list (all 434 of us) (I'd like to
welcome: esmith, k_kuramoto, chandramohan, jbrown, oluseyi, vinnie,
JACK, paul.smits, m.gregoire, rustyfulton, jimquinn666, jfwd, kev,
kwade, peter, chirag.shukla, swlee, kite102489, alan.larue,
ronan.golhen, nefleury, mauro, and smaflood)
Please let me know (email me) if you want to unregister. The latest
version of the program is on: www.nws.noaa.gov/mdl/NDFD_GRIB2Decoder/
----------- General News.
1) Reminder: the NWS Partner's Workshop meeting is this week. For more
details, talk with email@example.com. My personal involvement will
be on the morning of the 24th.
----------- News about this release:
I have just finished putting together version "1.53" (last one that I
announced was "1.51" on 5/18/2004).
This release is mainly focused on the "custom" option.
1) The NWS has started providing an experimental web service, which
allows one to select a "user defined sector" or "custom sub-grid" of the
NDFD. See "User defined GRIB homepage at
http://www.nws.noaa.gov/ndfd/grib.htm". Also see
This web service works by allowing the user to provide the lower left
and upper right lat / lon of a rectangle. (Note: The rectangle is only
a rectangle in the NDFD projected grid space, so it may take a little
experimentation to get it to cover the area that you are interested
in.) The NWS web server then uses a program to encode that part of the
NDFD in GRIB2, and send that data back across the web.
Advantages: This allows you to select your own sector, and retrieve
specifically the data you need and no more than that.
Disadvantages: It may be slower, since the code has to encode the data
in GRIB2 instead of just passing already encoded data across the web.
To alleviate this disadvantage, the NWS is restricting the use of "User
defined" aka "custom" grids to 15x15 degree areas. The current thinking
is that if you want more that 15x15 degrees at a time, you should get
the Conus data.
Degrib is capable of interacting with the web service, and "tkdegrib"
now has a sector called "custom". To adjust the lat/lon box for custom,
go to "File->configure", then on the "Custom Tab", type in the values
that you want.
Note 1: I believe the non-GUI (aka scripted) method of getting the data
works for the "custom" sector, but I haven't had a chance to try it.
Note 2: Currently the "generate images" button does not work for the
"custom" sector. I shall be working on that, but in the mean time, you
can use GrADS or ESRI ArcView, or ncView to view the data, or the
command line program with the -P option to probe the data.
2) GRIB1 bug: I hadn't paid attention to "Table 5" Time range
indicator. I do now, which means that the degrib code understands the
"P1 and P2 times" better. This means better "valid times" for GRIB1
3) Continued to work with the Ozone people as they straightened out
their meta data.
Please let me know if you have problems.