The National Centers for Environmental Prediction (NCEP) decodes, on an operational basis, upper air data from the Global Telecommunications System (GTS). ADP is an abbreviation for Automated Data Processing. It is a global synoptically sorted dataset. See Observational Data Processing at NCEP by Dennis Keyser and the NCAR/CGD discussion of Conventional Meteorological Station Data in TN 404. This is the data which NCEP uses in their models, so they apply many quality controls. Very important additional information. When stations fail to report over the GTS, or there are other data problems, we can not repair the information.

This dataset has the data which NCEP puts in their BUFR format. Software which extracts data from the BUFR file, and places it in a basic text file can be found in BUFRdecode_ADPuprair.tar. Since October 1999, NCAR has been using NCEP's software to convert this data to the ON29 format, to keep DS353.4 current. DS353.4 contains the same data types in ON29 format, from 1973 to the present.

Note that the BUFR format provides for more information than does ON29. Some new data types are carried in BUFR but not in ON29. Also, BUFR carries the original raw reports which NCEP collected from the GTS - ON29 does not.