Model Data Inventories

Table of Contents

Introduction

NCEP Numerical Weather Prediction (NWP) Model Data Sets and Reanalysis

NCEP NOAAPort Eta (NAM), GFS, and RUC

NCEP High Resolution (1 degree) Global Forecast System (GFS), and meso-Eta (12km)

NCEP North American Regional Reanalysis (NARR) (32km, 25 years)

Data Assimilation Models

Climate Model Data Sets

NOMADS Data Portals

Get Adobe Acrobat Reader

* Note * This page is an inventory page only! To access the data listed below, please use the Model Data Access Page

Introduction

NCDC maintains a repository of weather model output data sets, model input data sets (assimilation), and climate model data sets. These data sets include:

• Numerical Weather Prediction (NWP) model input produced by the National Centers for Environmental Prediction (NCEP);
• NWP gridded model output produced by (NCEP);
• NCEP/NCAR/DOE Reanalysis; and
• Global Climate Model (GCM) model data from the Geophysical Fluid Dynamics Laboratory (GFDL).

NCDC receives the NWP gridded data directly from NCEP and provides real-time access to the weather model forecast data. In addition to real-time NCEP model data, our repository also includes historical data from May 2002 to present. As a participant in the NOMADS project, NCDC serves as a portal that allows user access to numerical weather prediction model data and global climate model data at many other sites on the web in addition to the NCDC site. For example, you can find reanalysis, climate monitoring, and real-time high resolution NCEP models and data at the NCEP NOMADS site.

Use this page to locate data sets of interest and to view data set documentation. This page does not provide you access for plotting or retrieval. If you want to access the data, visit the Model Data Access page.

NCEP Weather Model Data Sets and Reanalysis

NCDC receives data sets from Numerical Weather Prediction (NWP) models in real-time via the NOAAPort Ingest System. The models are run at NCEP and include the Global Forecast System (GFS), the ETA Models, and the Rapid Update Cycle (RUC) Models. Plans to expand the repository include additional models (Ocean, Ensembles, etc.). The data sets contain gridded model output and are stored in GRIB format. The outputs contain analysis fields and forecast hours for multiple parameters and levels.

As the GRIB files are received they are archived off-line for long term storage. As they are received the files are also kept on-line for a period of time to provide fast access. Eventually the files are removed from on-line storage, but they can be retrieved from off-line storage and temporarily placed on-line for access.

The table below lists all the data sets we have on-line or archived at NCDC. Each entry in the table below provides you links to pages providing detailed metadata describing that data set. The following columns provide links to metadata:

• model docs - the NCEP technical documentation for this model.
• grid/scale - the grid specifications from the NCEP Office Note 388 page. For more grid details, see NAM Grid Domains and Grid Areas of Coverage.
• wmo - the WMO Headers for NCEP AWIPS Products provided over NOAAPORT. The sets of output parameters vary by model, grid, level, and forecast hour. Use this link to determine when and where each parameter is available.
• toc - the "table of contents" server for this data set. A toc for a model run lists the parameters, levels, and forecasts projections available in that run. In the NOAAPort data stream, not all NCEP model output parameters are present at all levels and forecast projections. Use this server to explore the contents of any file in the data set.
• vars/levs - a combined listing of both the variables and levels available for a model run.
• gds - the GrADS OPeNDAP/DODS server for this data set. Use the GDS server to view OPeNDAP/DODS metadata listings. Browse lists of files available using the GDS server at NCDC. For additional information about open distributed access across the Internet, see the Model Data Access Methods page.
• por - the period of record (por) for this data set. This page provides the date range of available on-line and off-line data. The range of on-line data for most models spans two years.
• snapshot - a sample "table of contents" from one run of that model over that grid. Use this link to quickly get a concise summary of parameters, levels, and forecast projections available for that particular model grid.

Documentation for Weather Model Data Sets
in NCDC Repository

NCEP Data Assimilation Datasets

The National Weather Service's National Center for Environmental Prediction (NCEP) runs a series of computer analyses and forecasts operationally. NCDC receives rerun/retrospective data sets from NCEP in real-time that contain the NCEP operational ready observation and restart files necessary to begin the Spectral Statistical Interpolation (SSI) cycling analysis. The collection of observations and restart files can be used to rerun the analysis cycling or global forecast system.

Climate Model Data Sets

Global Climate Models

The GFDL Data Portal provides access to the latest (and previous) Intergovernmental Panel on Climate Change (IPCC) output from Coupled Ocean-Atmosphere Global Climate Models (GCMs). The CM2.0 and CM2.1 Coupled Climate Models are available at GFDL's Data Portal. Documentation on these models can be found on the GFDL pages and in this PDF document from GFDL.

GFDL have also processed and have made availavbe on their NOMADS HTTP server, 100 year long time series of daily mean precipitation, maximum and minimum daily air temperature. NCDC NOMADS has placed a mirror of a selection of these datasets on it's GrADS Data Server (GDS), for easy subsetting and access.

An analysis of these datasets has been conducted by the NCDC NOMADS team. The results of the analysis are available in image format. These graphics were produced using select CM2.1 Model runs. The 'pr' (daily average precipitation flux (all types) ) field was run through a preprocess where the maximum value from each year was found at each grid cell for each year. Then, a linear regression was run using GrADS on each grid cell and the resulting 'trend' analysed. A similar analysis was proformed on surface air temperature 'tas' and on various 100 year Frich et al. indecies which were pre-computed at GFDL, including fd, cdd, hwdi, and r5d.

Older DecCen Coupled Climate Experiments

Pre-October 2004 climate model data sets are available at their DecCen Coupled Climate Experiments page. Documentation that describes the experiments can be found on the GFDL DecCen Climate Model web pages.

NOMADS Data Portals

NOMADS allows you to access numerical weather prediction model data and global climate model data at many other sites on the web in addition to the NCDC site. For a complete list of data sets by provider and by science discipline see NOMADS Data Availability.

Top of Page