0 - 10 Days Operational Models
Navy Global Environmental Model
The Navy Global Environmental Model (NAVGEM) is a global numerical weather prediction computer simulation run by the United States Navy's Fleet Numerical Meteorology and Oceanography Center. This model is run four times a day and produces weather forecasts out to 180 hours, one-way coupled to HyCOM, and is ESMF-compliant via the NUOPC layer. NAVGEM replaced NOGAPS, which had been running since 1982. NAVGEM uses the NRL-developed 4DVAR Naval Research Laboratory Atmospheric Variational Data Assimilation System-Accelerated Representor (NAVDAS-AR) for data assimilation. NAVGEM 1.3 has 425 spectral waves and 50 vertical levels for 31 km horizontal resolution.
Global Forecast System
Global Weather Forecast Model run by the National Centers for Environmental Prediction. It is a weakly coupled model with four components: atmosphere, ocean (HyCOM), land/soil (Noah), and sea ice model (KISS), a statistical extrapolation model. GFS evolved out of the earlier AVN aviation and MRF models; the NCEP NEMS (NOAA Environmental Modeling System) framework is ESMF-compliant. GFS has 1524 spectral waves with 64 vertical levels. Horizontal resolution is 13km. Data assimilation is provided by the Global Data Assimilation System (GDAS), a 3D-VAR technique.
Flow-Following Finite –Volume Icosahedral Model
FIM is the ESRL-developed global weather forecast model; it has been run at various resolutions. This model is designed differently than most other operational models currently in use. Rather than a spectral wave decomposition, FIM uses an icosahedral grid composed of over 650k cells instead of latitude/longitudinal grid space, but the same dynamical core as GFS.
Global Air-Land Weather Exploitation Mode
The US Air Force will run the Global Air-Land Weather Exploitation Model (GALWEM). This is an adaptation of the UK Meteorology Office (UKMO) Unified Model adjusted to the USAF’s operational needs. It is a 17 KM, 70 Level model using initialization fields from the UKMO. It is used to provide global fields for higher resolution regional models.