Model Data Access
NOMADS Web Interface

Introduction

National Oceanic and Atmospheric Administration (NOAA)
NCDC NOMADS Server: Model Data (Real-time and Historical)

Numerical Weather Prediction (NWP) Input and Output

North American Mesoscale (NAM, formally Eta)

Global Forecast System (GFS, formally AVN/MRF)

Rapid Update Cycle (RUC)

GDAS Model Input Assimilation Data

AWIPS NOAAPort Grids (historical only; reduced resolution and variable)

Ensembles

Low Res GFS Ensembles

Hi Res GFS Ensembles

NOMADS Global Ensemble Weather Prediction Forecast Probabilities

Reanalysis

North American Regional Reanalysis (NARR) (32km, 1979 to present)

Global Reanalysis (R1 & R2)

Climate

Coupled Climate Forecast System (CFS)

Limited GFDL CM2.X Coupled Climate Model data from NCDC NOMADS Server

NCDC In-situ Reference Quality Datasets (NCDC)

Blended Ocean Winds

Reynolds SST

Global Historical Climate Network (GHCN)

Integrated Global Radiosonde Archive (IGRA)

Paleoclimate Datasets

NCDC Mirror R/T NOMADS Server (backup server for NCEP real-time)

NOMADS Live Access Server
 

NCEP R/T NOMADS Server (Real-Time NOMADS server with rotating access up to two weeks)
 

National Weather Service (NWS)

National Digital Forecast Database
 

Geophysical Fluid Dynamic Laboratory (GFDL)

GFDL's Data Portal and NOMADS Server
 

National Oceanographic Data Center (NODC)

NODC AVHRR Pathfinder Version 5.0 SST Dataset
 

NOAA Earth System Research Laboratory (ESRL) formerly Forecast Systems Laboratory (FSL)

MADIS NOMADS Server
 

National Aeronautics and Space Administration (NASA)

MERDIS MARS (in development)
 

Department of Energy (DOE)

Program for Climate Model Diagnosis and Intercomparison (PCMDI)

Atmospheric Model Intercomparison Project (AMIP)
 

National Center for Atmospheric Research (NCAR)

NCAR Data Portal

Community Climate Model (CCM)
 

Australian Bureau of Meteorology (BOM)

NOMADS Server
 

NOAA's Air Resources Laboratory is also an excellent model data resource (ARL)

Gridded Meteorological Data Archives

Data Access User Guide

Introduction

This web site provides access to the model data repository at NCDC. This repository contains both archived (i.e., off-line) and on-line model data. We provide a variety of ways to access our weather and climate model data. You can access the on-line data using traditional access methods (web-based or ftp), or you can use open and distributed access methods promoted under the collaborative approach called the NOAA Operational Model Archive and Distribution System (NOMADS). With the NOMADS Web Interface you can create, display, and download plots, use ftp to download parameters and files, and use the NOMADS Distributed Data Server using DODS/OPeNDAP and the GrADS-DODS/OPeNDAP Server (GDS) to access the data directly from your preferred client or desktop. You can also perform remote calculations using scripts under the GDS.

To see what datasets we have available, first vist the NCDC Model Data Inventories section to locate datasets of interest and view dataset documentation.

After you determine which datasets you want to further explore, visit the Data Access Guide page and learn about the different access methods and features provided.

To browse the inventories, directly read and analyze data, or retrieve model data visit the sections below. The following access functions are provided.

• plot - allows you to build a collection, then select parameters from the collection, and create plots
• grid/scale - type, resolution and domain of grid
• ftp4u - allows you to build a collection, select files or parameters from the collection, and ftp selected data to our anonymous ftp server.
• ftp - browse lists of files on our server and download files using the ftp protocol.
• http - browse lists of files on our server and use your browser to download files.
• gds - access GrADS DODS/OPeNDAP server for this dataset. Use the GDS server to obtain the URL for files you want to access from your desktop DODS/OPeNDAP enabled client.
• OPeNDAP - access DODS/OPeNDAP server for this dataset. Use the DODS server to obtain the URL for files you want to access from your desktop DODS/OPeNDAP enabled client.

NCEP High Resolution Global Forecast System (1 degree GFS), North American Mesoscale (12km NAM), and Rapid Update Cycle (20km RUC)

The table below lists the weather model datasets we have on-line or archived at NCDC. Each entry in the table below provides you links to access methods for that dataset. See the Section Above for descriptions of these access methods. Note: These data may be delayed up to one day. For real-time access go to the NCEP R/T NOMADS.

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

Documentation

• NCEP North American Regional Reanalysis Homepage
• NARR Overview
• NARR Presentation to NESDIS Archive Requirements Council (ARC)
• NCDC DSI-6175 NARR Dataset Documentation
• Differences between NARR A and B Files
• Contents of NARR Output GRIB Files
• Fixed Field Data & Information

NARR fields use Earth relative winds, which do not need adjustment when used with GrADS and GDS.

Monthly Means:
The NARRMON dataset contains a monthly average (computed at NCEP) of all the fields in the NARR. The NARRMON-3hr dataset is a monthly average of all fields, seperated into eight three-hour time periods for each day throughout a month.

NCEP GFS Ensemble Probabilities

The following interfaces are testbed capabilities to multiple members of the NCEP Ensembles run under the Global Forecast System. These interfaces allow user selectable flow-dependant probabilities predictions of several meteorological sensible weather elements. These pages are in development. Please report feedback to NOMADS.ncdc@noaa.gov.

NOMADS Ensemble Probability Tool

Threshold percentages (temp/wind/precip) only

Threshold percentages with bar graph (long version)

Coupled Climate Forecast System

The Climate Forecast System (CFS) is a fully coupled model representing the interaction between the Earth's oceans, land and atmosphere. This model became operational in August 2004, and has been run in retrospective mode back 25 years to 1981.

Presently, NCDC-NOMADS does not maintain an archive for the Climate Forecast System data. There are plans to archive this dataset in the future.

Users seeking access to CFS archived and real-time data should visit the National Centers for Environmental Prediction's CFS homepage at:
http://cfs.ncep.noaa.gov/

Available on the site are retrospective daily and monthly data, climatologies, links to operational CFS model runs, CFS documentation, news, and other products.

NCDC Climate Reference Datasets

Below are several operational data sets provided by the NCDC and NOMADS.

NODC AVHRR Pathfinder Version 5.0 SST Dataset

The 4 km AVHRR Pathfinder Version 5.0 SST Project (Pathfinder V5) is a new reanalysis of the AVHRR data stream developed by the University of Miami's Rosenstiel School of Marine and Atmospheric Science (RSMAS) and the NOAA National Oceanographic Data Center (NODC). This reprocessing uses an improved version of the Pathfinder algorithm and processing steps to produce twice-daily global SST and related parameters back to 1985, at a resolution of approximately 4 km, the highest possible for a global AVHRR data set. Temporal averages for 5-day, 7-day, 8-day, Monthly, and Yearly periods are also produced. Current key improvements over the original 9 km Pathfinder SST data set include a more accurate, consistent land mask, higher spatial resolution, and inclusion of sea ice information. Other improvements are under development and will be implemented in the next reprocessing, which will commence in mid-2004.

NCEP Model GDAS Assimilation Dataset (in BUFR & GRIB format)

Below are several operational data sets provided by the NCDC and NOMADS.

Please see NCEP (Keyser) for additional background information on GDAS and other NCEP models.
http://www.emc.ncep.noaa.gov/mmb/papers/

We will be adding plotting and ftp capabilities as programs are completed.

Climate Model Datasets

Through the NOMADS Collaboration, model output and documentation from a set of multi-century experiments performed using GFDL's CM2.0 and CM2.1 global climate models are being made available at GFDL's NOMADS Data Portal. Datasets are available at their GFDL CM2.x Coupled Climate Models page.

The Community Data Portal (CDP) is a collection of earth science datasets from NCAR, UCAR, UOP, and participating organizations in the following research areas:

• Oceanic
• Atmospheric
• Space Weather
• Turbulence

Paleoclimate Datasets

The paleoclimate model data sets available here are derived primarily from climate model experiments associated with peer reviewed scientific publications. The archive includes many of the experiments performed as part of the Paleoclimate Model Intercomparison Project (PMIP), plus other, PMIP-like experiments. Also included here are other model runs such as transient simulations of the past 1,000 years, and some data sets related to model forcing and model boundary conditions. Additional information on paleoclimate model data sets, including tools to access and plot model data and a web form to search for data, are available on the paleoclimate modeling page.

Paleoclimate model output on NOMADS GrADS Data Server
Paleoclimate modeling page at NCDC
PMIP II web site

National Digital Forecast Database

NCDC NOMADS provides access to NCDC's archive of the National Weather Service National Digital Forecast Database (NDFD). Due to the volume of this dataset, access is provided through the NOMADS automated offline order system for one day of data. To place an order, use the access point below. Due to current incompatibilities with our plotting software, the native GRIB2 NDFD data is converted to GRIB1 after the data has been pulled from the HPSS archive.

Access NDFD offline order interface

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