http://www.nco.ncep.noaa.gov/pmb/codes/GRIB2

NCEP codes for decoding and encoding data in GRIB2 format

Note: These codes are provided as is for the use of NCEP data users. NCEP does
not and can not provide any support for them.

http://www.weather.gov/disclaimer

Disclaimer
                                                   National Weather Service
                                                   National Headquarters
[...]

Use of Data and Products

  The information on National Weather Service (NWS) Web pages are in the public
  domain, unless specifically noted otherwise, and may be used without charge
  for any lawful purpose so long as you do not: 1) claim it is your own (e.g.,
  by claiming copyright for NWS information -- see below), 2) use it in a
  manner that implies an endorsement or affiliation with NOAA/NWS, or 3)
  modify its content and then present it as official government material. You
  also cannot present information of your own in a way that makes it appear to
  be official government information.

  Use of the NWS name ("National Weather Service") and/or visual identifier
  are protected under trademark law and may not be used without permission
  from the NWS. Use of the NWS name and/ or visual identifier to identify
  unaltered NWS content or links to NWS web sites are allowable uses.
  Permission may be requested for this use at
  http://www.weather.gov/logorequest. Permission is not required to display
  unaltered NWS products which include the NWS name or NWS/NOAA visual
  identifier as part of the original product. Neither the name nor visual
  identifier may be used, however, in a manner that implies an endorsement or
  affiliation with NOAA/NWS.

  Before using information obtained from any NWS Web page special attention
  should be given to the date and time of the data and products being
  displayed. 

  The user assumes the entire risk related to its use of information on NWS
  Web pages. NWS is provides such information "as is," and NWS disclaims any
  and all warranties, whether express or implied, including (without
      limitation) any implied warranties of merchantability or fitness for a
  particular purpose. In no event will NWS be liable to you or to any third
  party for any direct, indirect, incidental, consequential, special or
  exemplary damages or lost profit resulting from any use or misuse of this
  data.

  As required by 17 U.S.C. § 403, third parties producing copyrighted works
  consisting predominantly of the material appearing in NWS Web pages must
  provide notice with such work(s) identifying the NWS material incorporated
  and stating that such material is not subject to copyright protection.

[...]