NOAA / NWS's Meteorological Development Laboratory
Degrib (NDFD GRIB2 Decoder)
Subject: Degrib 1.42
Date: Fri, 23 Jan 2004 17:03:45 -0500
From: Arthur Taylor
You all have the unique distinction of being registered on my degrib
(aka NDFD_GRIB2Decoder) mailing list (all 298 of us) (I'd like to
welcome: stephen.leavitt, ppad75, tmalampy, fuka_d, jackie,
cycloneweather2002, abilling, tsstroh, srentals, bryan.ray, Pat.Murphy,
bryan, rhkelsey, daryl314, fwide, jefferson, bruce, newiind2, thehaas,
gregg, ron.holmes, tkenthome, paul, raziulmollah, krisb, jduflost,
pnmc3, NDFD-19-ainglis, jason, rmathis, bsmyth, edward.amrhein,
jack.katzfey, rllewellyn, hawojdylak)
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.
----------- News about this release:
I have just finished putting together version "1.42" (last one that I
announced was "1.40" on 12/24/2003).
This release is mainly focused on enhancing the meta data to deal with
RUC and ETA GRIB1 / GRIB2 messages, and dealing with some "weather
string" issues. In addition, Doug Marcy was kind enough to create some
ESRI Legend files (located in /degrib/arcview/poly_legend, and
/degrib/arcview/point_legend) so that the ESRI crowd can readily use the
same color schemes that are on the NDFD web pages.
1) Incorporated a number of Doug Marcy's suggestions along with his ESRI
legends. In addition to the ESRI legends, he provided a "how to use
tkdegrib with ESRI" document. In it he pointed out a few glitches,
which I think I have now fixed.
2) Enhancement to meta specs: I downloaded the most recent GRIB2 specs
from the web, and got the current NCEP GRIB2 local tables. I also added
the ability to lookup the ETA variables, and typed in their
abbreviations from the GRIB1 specs. In addition I created surface level
lookup routines, and added them to the inventories (see item 3)
3) Changed my perspective to emphasize the level that the data is on.
In NDFD we are only concerned about element, and forecast time, since
all the data is on the surface. For the RUC data, they are concerned
about element, and surface since a single file typically contains only
one set of time. My inventories didn't work very well with RUC, since I
didn't have a surface list. I do now.
4) Enhanced the Weather code. Originally degrib didn't handle "OR" or
"MX" as a "hazard". Although that is not in the official guidance on
weather keys (see
http://www.nws.noaa.gov/datamgmt/doc/GRIB2_encoding.html), it was felt
that degrib should treat it as if it were an "^", when creating the
5) I have added the following types of weather (not currently in the
"BN" -> "Blowing Sand", "ZF" -> "Freezing Fog", "IC" -> "Ice Crystals",
"IF" -> "Ice Fog", "VA" -> "Volcanic Ash", "ZY" -> "Freezing Spray",
"WP" -> "Waterspouts".
There may be other weather types and coverages that are used locally,
that aren't in the national documentation. If you run into problems
with local weather keys, please let firstname.lastname@example.org know, and they
will forward you to the correct local contact.
6) Upgraded the "NDFD-Simple-Weather-Code" from the original (version 1)
to the new (version 2). There may be some bugs in it, and if you need
the original version, from the command line, there is a "-SimpleVer 1"
option (for original) or "-SimpleVer 2" for the new version. The
default is the new version.
7) Switched to using "emapf-c" so degrib can handle a non spherical
earth. Most GRIB messages use a spherical earth, but the creators can,
either by accident, or intentionally use an ellipsoidal earth. "degrib"
can now handle the ellipsoidal earth, so it won't crash if you run into
such a GRIB message.
8) Fixed the output of "lat/lon" projection to be from -180..180,
instead of 0..360. ESRI prefers the -180..180, while GRIB prefers
0..360. This should help people with using NCEP's 1/2 degree world grid.
9) Found and fixed a few bugs with the MS-Windows98 version (thanks
Pat), and with the GUI on the UNIX platforms.
Please let me know if you have problems.
(Art in MDT (Mountain Daylight Time) :-) )
("Big A" for Glasgow's WCM :-) )