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The NOMADS Project

To address a growing need for remote access to high-volume numerical weather prediction and global climate models and data, NCEI, along with the National Centers for Environmental Prediction (NCEP) and the Geophysical Fluid Dynamics Laboratory (GFDL), initiated the NOAA National Operational Model Archive and Distribution System (NOMADS) project. NOMADS addresses model data access needs as outlined in the U.S. Weather Research Program (USWRP) "Implementation Plan for Research in Quantitative Precipitation Forecasting" and Data Assimilation to "redeem practical value of research findings and facilitate their transfer into operations." The NOMADS framework was also developed to facilitate climate model and observational data intercomparison issues as discussed in documents such as the Intergovernmental Panel on Climate Change (IPCC 1990, 1995, 2001) and the U.S. National Assessment (2000). NOMADS is being developed as a "unified climate and weather archive" so that users can make decisions about their specific needs on time scales from days (weather), to months (El Niño), to decades (climate change).


NOMADS is a network of data servers using established and emerging technologies to access and integrate model and other data stored in geographically distributed repositories in heterogeneous formats. NOMADS enables the sharing and comparing of model results and is a major collaborative effort, spanning multiple government agencies and academic institutions. The data available under the NOMADS framework include model input and numerical weather prediction (NWP) gridded output from NCEP, and global climate models (GCMs) and simulations from GFDL and other leading institutions from around the world. The goals of NOMADS are to

  • Improve access to NWP and GCM's model output and provide the observational and model data assimilation products for regional model initialization and forecast verification
  • Promote improvements to operational weather forecasts
  • Develop linkages between the research and operational modeling communities and foster collaborations between the climate and weather modeling communities
  • Promote product development and collaborations within the geo-science communities (ocean, weather, and climate) to study multiple Earth systems using collections of distributed data under a sustainable system architecture

Project Components

The following centers host NOMADS nodes.

National Centers for Environmental Information

NCEI NOMADS provides near real-time access to

  • Most of NCEP's operational datasets (available shortly after distribution)
  • A long-term archive for all datasets
  • Several other datasets

National Centers for Environmental Prediction

NCEP provides 24x7 real-time support at the NCEP–NOMADS high-availability server. This server provides

  • Access to NCEP's operational datasets as they are being generated
  • A short-term archive of up to a month for most datasets
  • 24x7 operational monitoring by NCEP staff
  • A geographically diverse backup server to insure operational availability
  • Access to nonoperational research and development servers used for customer testing

National Coastal Data Development Center

OceanNOMADS is a NOMADS node dedicated to NOAA and Navy ocean models. Currently available are Real Time Ocean Forecast System (RTOFS)–Atlantic region, as well as selected regions of the Navy Coastal Ocean Model and Navy Intra-Americas Sea model.


NOMADS fosters system interoperability by integrating legacy systems with emerging technologies and existing metadata conventions used for models and observational data. NOMADS relies on local decisions about data holdings. Loosely combining legacy systems, while developing new ways to support access to valuable data, permits NOMADS to work on the cutting edge of distributed data systems. In this effort, no single institution carries the weight of data delivery since data are distributed across the network and served by the institutions that developed the data. The responsibility for documentation falls on the data generator with Advisory Panels ensuring overall quality and systems standards and determining which NOMADS data are required for long-term storage. Further, NOMADS in no way precludes the need for national centers to maintain and support long-term archives. In fact, NOMADS and secure data archives are mutually supportive and necessary for long-term research. The primary science benefit of the NOMADS framework is that it enables a feedback mechanism to tie government and university research directly back to the NOAA operational communities, numerical weather prediction quality-control and diagnostics processes at NCEP, and climate model assessments and intercomparisons from around the world.


Researchers and policy makers alike now expect our national data assets to be easily accessible and interoperable, regardless of their physical location. As a result, an effective interagency distributed data service requires coordination of data infrastructure and management extending beyond traditional organizational boundaries. Under NOMADS and its collaborators, NOAA will be at the forefront of a worldwide-distributed data-serving network. This will allow users at any level to obtain weather and climate information. It will enable them to make better, informed decisions about how nature will impact their future, either in their life or in their business decisions. For further information, contact us through NOMADS email.