NOAA / NWS's Meteorological Development Laboratory
Degrib (NDFD GRIB2 Decoder)
Date: Thu, 18 Oct 2007 09:21:42 -0400
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The focus of release 1.88 is to support the 12 new CPC products which are being added to the NDFD.
------- General News (see http://www.nws.noaa.gov/om/notif.htm#tin):
TIN07-71: On 10/18/2007, there will be an addition of 12 climate outlook probability elements to the NDFD
There has been a yahoo group (firstname.lastname@example.org) created to discuss degrib (usage etc).
Based on: http://www.wmo.ch/pages/prog/www/WMOCodes/GRIB.html,
the 4th version of the GRIB edition 2 specs will become operational on 11/7/2007.
------- Details about release: 1.88 (last one was 1.87 on 9/20/2007)
1) Introduced 12 new CPC elements. These are (temp, precip) (above, below) average for (6 days (days 8-14), 1 month, and 3 months). See the "Days8-450 folder". They are being labeled in the NDFD as follows: "tmpabv14d", "tmpblw14d", "prcpabv14d", "prcpblw14d", "tmpabv30d", "tmpblw30d", "prcpabv30d", "prcpblw30d", "tmpabv90d", "tmpblw90d", "prcpabv90d", "prcpblw90d".
2) Attempted to resolve a backward incompatibility issue with the NCEP GRIB2 library. The 1.0.2 version stored lower and upper probability limits as unsigned integers, while 1.0.4 stored them as signed integers. Some of NCEP's models stored negative values for these entries using the 1.0.2 version, which meant that they used "2's complement + 1". Unfortunately 1.0.4 assumes they were stored the correct way using "a sign bit + absolute value", so it returns an incorrect value. I developed a way to read either a 1.0.2, or 1.0.4 packed negative value and get the intended answer.
3) Fixed a glitch with the ndfd.ini file for some of the newer Gridded MOS elements.
4) Upgraded from 1.0.4 to 1.0.5 of the NCEP GRIB2 library.
5) Updated NCEP local use tables (as of 10/16)
6) Added checks to make sure when saving to .shp (poly and point) that we don't exceed the maximum number of records the format will allow. The limits are: 23,860,928 records for small polygons, and 153,391,685 records for point.
Trivia: Degrib turns 5 years old on 11/5/2007. This is based on when I emailed my first "release note" to myself and 2 other people.
------- Please let me know if you have problems.