NCEP Numerical Forecast/Analysis Systems

This animated precipitation map above an example of a 6 day interval from a run of the Global Forecast System (GFS).

Data from the NCEP numerical guidance systems listed below are available through NOAA's National Operational Model Archive and Distribution System (NOMADS).

  • Global Forecasting System
    The Global Forecast System (GFS) is the cornerstone of NCEP's suite of numerical guidance, providing forecasts at 13 km resolution to 16 days. The GFS is used for initial and/or boundary conditions for other NCEP systems for regional, ocean and wave prediction.
  • Global Ensemble Forecast System
    The GEFS is NCEP's 31-member global ensemble prediction system using the NCEP Global Model, running to 16 days at 25 km resolution (to 30 days at 0000 UTC). Initial perturbations are created with an Ensemble Kalman Filter scheme, and stochastic physics schemes are used to represent model error.
  • NCEP Data Assimilation
    The NCEP hybrid ensemble data assimilation system with the Grid-Point Statistical Interpolation (GSI) analysis is used to generate initial conditions for NWS operational global, regional, mesoscale, rapid refresh, Real-Time Mesoscale Analysis (RTMA) and hurricane guidance systems.
  • Climate Forecast System
    Climate Forecast System (CFS) is a fully-coupled global model that simulates the interaction between the Earth's atmosphere, oceans, land and sea ice. CFS provides forecasts out to nine months.
  • North American Mesoscale
    The North American Mesoscale Model (NAM) is a regional weather forecast model covering North America at 12 km horizontal resolution, with nested 3 km domains over the CONUS, Alaska, Puerto Rico, and Hawaii. It uses the NEMS version of the Non-Hydrostatic Meso Model on B-grid (NMMB)
  • Rapid Refresh
    The Rapid Refresh is an hourly-updated assimilation/modeling system operational at NCEP, developed at NOAA's Earth Systems Research Laboratory. The RAP covers North America and is complemented by the High-Resolution Rapid Refresh (HRRR) system
  • High-Resolution Rapid Refresh
    The HRRR is a 3-km resolution, hourly updated, convection-allowing forecast system, developed by NOAA's Earth System Research Laboratory. Radar data is assimilated in the HRRR every 15 minutes over a 1-hour period adding further detail to that provided by the 13km Rapid Refresh system.
  • Short-range Ensemble Forecast
    The SREF has 26 members (13 WRF-ARW,13 NMMB) generated from a diverse set of analyses/model physics at 16km resolution over North America, made 4 times/day to 87h. The products include ensemble max/min/median/mean, spread, and probability, and are available in raw, bias-corrected, or downscaled format.
  • High-Resolution Ensemble Forecast
    The High-Resolution Ensemble Forecast system employs NCEP's operational convection-allowing (~3km) systems to generate ensemble products, using current/time-lagged forecasts from the HiresWindow run (ARW/FV3LAM over CONUS, Alaska, Hawaii, Puerto Rico). For the CONUS, the HRRR and the NAM 3km nest is also used.
  • Global Real-Time Ocean Forecast System
    The Real-Time Ocean Forecast System (Global RTOFS) is based on an eddy-resolving version of the HYCOM (HYbrid Coordinates Ocean Model) at 1/12 degree resolution, run once/day at 00z. Each run starts with 48-h of hindcasting and produces full-volume forecasts from the initial time out to 8 days.
  • Global Wave Model (WAVEWATCH III)
    The NCEP operational global wave model (WAVEWATCH III) runs as coupled component to the NCEP Global Forecast System (GFS) and Global Ensemble Forecast System (GEFS)
  • HWRF
    The NCEP Hurricane WRF (HWRF) system is one of the two on-demand hurricane models run at NCEP. HWRF uses the WRF version of the Non-Hydrostatic Mesoscale Model (WRF-NMM), and is coupled to the Princeton Ocean Model.
  • HMON
    HMON (Hurricanes in a Multi-scale Ocean-coupled Non-hydrostatic Model) is one of the two on-demand hurricane forecast systems run at NCEP. HMON uses the Non-hydrostatic Multi-scale Model on a B grid (NMMB) dynamic core. It includes vortex relocation, but has no data assimilation.
    The Real-Time Mesoscale Analysis (RTMA), UnRestricted Mesoscale Analysis (URMA) and the Real Time Mesoscale Analysis with Rapid Updates (RTMA-RU) provides 15-min to 1-h surface analyses at 2.5-3 km resolution for the CONUS, Alaska, Hawaii, Puerto Rico, and Guam.
  • NCEP Sea Surface Temperature Analysis
    NCEP has developed the Near Surface SST (NSST) to do direct analysis of SST in the GDAS using marine observations and satellite radiances. The NSST incorporates SST diurnal variability in the 16 day GFS forecast.
  • NCEP Air Quality Model
    The NOAA National Air Quality Forecast Capability (NAQFC) provides 72-h forecasts of ozone and fine particulate matter surface concentration from 0600 and 1200 UTC from the EPA Community Model for Air Quality (CMAQ). Predictions are made over the CONUS, Alaska, and Hawaii.
  • GEFS Aerosol Model
    The GEFS-Aerosol system is a global in-line aerosol forecast system which runs as a special member of the NCEP GEFS system, using the GFS (FV3 version) as the forecast component; the aerosol component is the GSD Chemistry Model (GSDCHEM). It makes 120-h forecasts of dust, sea salt, sulfate, and carbonaceous aerosols.
  • N.American Land Data Assimilation System
    The NLDAS runs uncoupled land-surface models driven by NAM atmospheric forcing and observed surface data. In NCEP Production it runs in near-real-time, and was run off-line in a 30-year retrospective. It generates hourly surface forcing and simulation of surface energy fluxes.
  • Nearshore Wave Prediction System
    The Nearshore Wave Prediction System (NWPS) provides on-demand, high-resolution nearshore wave model guidance to U.S. coastal WFOs, triggered in real time by forecast wind grids prepared and submitted by the individual offices.
  • North American Ensemble Forecast System
    A joint project involving the Meteorological Service of Canada (MSC) in Canada, the National Weather Service (NWS) in the United States, and the National Meteorological Service of Mexico (NMSM) in Mexico providing numerical weather prediction ensemble guidance out to 16 days.
  • Great Lakes Wave Model (WAVEWATCH III)
    The NCEP Great Lakes Wave production system runs the WAVEWATCH III model, forced with atmospheric data from NCEP's North American Mesoscale Model (NAM) and the National Digital Forecast Database (NDFD)