DSS presents a regional synoptic set of 6 hourly upper air reports centered over North America, operationally collected by the National Centers for Environmental Prediction (NCEP). These include radiosondes, pibals and aircraft reports from the Global Telecommunications System (GTS) and satellite data from the National Environmental Satellite, Data, and Information Service (NESDIS). The reports can include pressure, geopotential height, temperature, dewpoint depression, wind direction and speed. This data is the primary input to the ETA Data Assimilation System (EDAS)/NAM Data Assimilation System (NDAS starting Jan. 23, 2005), which is used to make forecasts and the Final Analyses (FNL). DS351.0 provides global data coverage over the same time period.

The ADPUPA data includes land and ship launched radiosondes and pibals launched at 6 hourly intervals. Data may be available at up to 20 mandatory levels from 1000mb to 1mb, plus a few significant levels. The AIRCFT data includes commercial, some military and reconnaissance reports. They are flight level reports at 6 hourly intervals. The SATWND data includes winds derived from cloud drift analysis. The AIRCAR data includes data from aircraft takeoffs and landings at 6 hourly intervals

This dataset is maintained in NCEP BUFR format, and updated monthly by DSS using weekly files prepared by NCEP. Software which extracts data from the BUFR file, and places it into a basic text file can be found in BUFRdecode_ADPuprair.tar. Data archived within this dataset spans the period from October 2000 to near current. DS353.4 provides global data from 1973 to near current in NMC Office Note 29 (ON29) format. BUFR format reports contain additional information that is not carried over to ON29 format, including the the original raw GTS string reports.

NCEP does some operational Quality Control (QC) on the data which sets some QC flags in the reports to qualify, but not quantify any corrections. After the data is used to prepare the FNL analyses, no additional corrections are made. Older data is not reprocessed with newer procedures.

More information is available.