DSS presents a global synoptic set of surface data reports. These were operationally collected by NCEP into three-hourly or six-hourly files, which in recent years can include hourly and even some 20-minute reports. They include land and marine reports received via the Global Telecommunications System (GTS). This dataset is DSS' primary surface observation set. NCEP uses Automated Data Processing (ADP) to decode and reformat the GTS reports. The NCEP document Observational Data Processing at NCEP and the NCAR document TN404 An Introduction to Atmospheric and Oceanographic Datasets, (chapter 3) discuss the collection of this data in greater detail.

The ADPSFC data includes these land surface station report types: SYNOP, METAR, and beginning in the mid 1990s, AWOS and ASOS. The SFCSHP data includes these marine surface report types: moving ship, fixed ship, MARS (moving and fixed) and buoy (moored and drifting). There are thousands of reports every six hours. An enumeration of this, available in our inventory summaries, shows how the volume has increased over the years. Similar information since 1997 is not available, but the counts have increased considerably. This is because NCEP began collecting hourly reports and in limited regions, 20-minute reports, in the late 1990s. The reports may include pressure, temperature, dewpoint depression, wind direction and speed. Precipitation data has been decoded for the U.S. and Canada.

This dataset is in an ASCII character format, known as the NMC Office Note 29 (ON29) format. This is a popular dataset with MM5, WRF and RAMS users - see this.It is updated monthly by converting the weekly BUFR files prepared for DSS by NCEP. The BUFR files are kept in DS461.0. The data is free, through the DS464.0 data page. MORE