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  MADIS User Resources

MADIS User Resources


MADIS subscribers have access to an integrated, reliable, and easy-to-use database containing the real-time an archive of saved real-time observational datasets. Also available are real-time gridded surface analyses. The surface analyses grids assimilate all of the MADIS surface datasets (including the highly-dense integrated mesonet data). The grids are produced by the Rapid Update Cycle (RUC) Surface Assimilation System (RSAS), which incorporates a 15-km grid stretching from Alaska in the north to Central America in the south, and also covers significant oceanic areas. The RSAS grids are valid at the top of each hour, and are updated every 15 minutes.

To gain access to MADIS' observational database, start by filling out a data application request. This will help the MADIS team assess your needs and help open the flood gates of data flowing to meet your particular needs.

Some of the MADIS data sets have been restricted by the provider. If a data set of interest is restricted please let us know via the application process why access should be permitted.

MADIS ingests data files from NOAA data sources and non-NOAA data providers, decodes the data and then encodes all of the observational data into a common format with uniform observation units and time stamps. Quality control checks are conducted and the integrated data sets are stored in the MADIS database with a series of flags indicating the quality of the observation from a variety of perspectives (e.g. temporal consistency and spatial consistency), or more precisely, a series of flags indicating the results of various QC checks. MADIS users and their applications can then inspect the flags and decide whether or not to use the observation. MADIS data is made available to the enterprise using multiple data transfer protocols via the Internet:

The datasets in the MADIS database are stored in netCDF files. This is the file format that is used when users request MADIS data using either the ftp or LDM protocols. MADIS provides an Application Program Interface (API) and related utility programs, which allow easy access to MADIS observations without having to develop a program for reading netCDF files. The API allows each user to specify station and observation types, as well as QC choices, and domain and time boundaries. Many of the implementation details that arise in data ingest programs are automatically performed. Users of the MADIS API, for example, can choose to have their wind data automatically rotated to a specified grid projection, and/or choose to have mandatory and significant levels from radiosonde data interleaved, sorted by descending pressure, and corrected for hydrostatic consistency. The API is designed so that the underlying format of the database is completely invisible to the user.

The MADIS database and API are freely available to interested parties in the meteorological community.

For users interested in the MADIS RSAS grids, the RSASDUMP utility can be used to output the data in plain text.

Users wanting access to MADIS data via web services are provided with data viewers and graphical displays. MADIS Text/XML Viewer accounts are recommended for those who have a need for data on-demand, as contrasted with continuous real-time access. In general, users who require a continuous datafeed will get better performance by accessing the data via ftp or LDM. Also note that at this time the Text/XML viewer currently only supports the MADIS surface observation datasets. The unrestricted data are available from the links below. All users should read the Data Use Policy and the Disclaimer in the MADIS Data Application. Users eligible for the restricted mesonets should request a Text/XML Viewer account.

Text/XML Displays

Graphical Displays


MADIS data files are compatible with:

The AMET tool is provided to the air quality modeling community by the Community Modeling & Analysis System at the University of North Carolina at Chapel Hill.

The current observation pre-processor package that's part of the Weather Research and Forecasting (WRF) variational data assimilation package includes a converter that will convert some of the MADIS datasets into the little_r text format that is then sent to the variational analysis. The MADIS datasets that are currently supported include mesonet, aircraft, ASOS and other METAR, Canadian SAO's, maritime (including ships, buoys and C-MAN stations), radiosondes, aircraft, and GOES satellite winds.

The WRF-Var group has a new version of a direct-to-MADIS interface, which will add support for profiler data, in their testing system, but have not announced plans for incorporating this into a version release.

Related Links

Last updated 22 March 2017