Pacific Northwest WRF Ensemble Member Descriptions

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Ensemble Members Using Standard Physics
Member(s) Initializing Model PBL Land Surface Model Surface Layer Option Radiation Microphysics Cumulus WRF Code Version Other Parameters
gefs01-gefs10 NWS Global Ensemble Forecast System (GEFS) YSU Noah-MP Revised MM5 Monin-Obukhov RRTMG Longwave and Shortwave Thompson Grell-Freitas Ensemble 4.1.3
    As of 2026030500 run, testing 2 options more like WRF 3.7.1:
  • use_mp_re=0 do not use effective radii from MP in RRTMG
  • use_theta_m=0 use dry theta in dynamics
  • leaving hybrid_opt=2
arpg or ARPEGE Meteo-France ARPEGE Model
  • No 6th-order diffusion
  • FDDA nudging on 36-km domain
  • diff_opt = 2
CMC or cmcg Environment Canada Global Deterministic Prediction System
dwdi German ICON Model
gasp Australian Bureau of Meteorology GASP Model
ecmwf European Centre for Medium-Range Weather Forecasts
IFS Model Open Data
ecaifs European Centre for Medium-Range Weather Forecasts
AIFS Machine Learning Data
wrf-gfs or WRFRT NWS GFS Model
This is our UW real-time 36/12/4-km WRF run.
ukmo discontinued May 26 2026 UK Met Office Unified Model
ngps discontinued Feb 2026 NAVY GEM Model

Ensemble Members Using Alternate Configurations
Member(s) Initializing Model PBL Land Surface Model Surface Layer Option Radiation Microphysics Cumulus WRF Code Version Other Parameters
HRRR NWS GFS Model MYNN 2.5-level TKE Scheme RUC LSM MYNN Surface Layer RRTMG Longwave and Shortwave Aerosol-aware Thompson Scheme Grell-Freitas Ensemble 4.1.3
  • 6th-order numerical diffusion, but prohibit up-gradient diffusion
  • no FDDA on 36-km domain
  • diff_opt = 1
nofdda NWS GFS Model YSU Noah (was Noah-MP through 2026062212) Revised MM5 Monin-Obukhov RRTMG Longwave and Shortwave Thompson Grell-Freitas Ensemble 4.1.3 Identical to WRF-GFS except:
  • no grid nudging for the 36-km domain, no FDDA
gfswrf3 NWS GFS Model YSU Noah-MP Revised MM5 Monin-Obukhov RRTMG Longwave and Shortwave Thompson Grell-Freitas Ensemble 3.7.1 Identical to WRF-GFS except version 3.7.1 does not have:
  • use_theta_m so uses dry theta in dynamics
  • use_mp_re so does not use effective radii computed in MP schemes in RRTMG
  • hybrid vertical coordinate
wrf4p3 NWS GFS Model YSU Noah-MP Revised MM5 Monin-Obukhov RRTMG Longwave and Shortwave P3 1-category plus double-moment cloud water Grell-Freitas Ensemble 4.1.3 Same as WRF-GFS
wrf4drag NWS GFS Model YSU Noah-MP Revised MM5 Monin-Obukhov RRTMG Longwave and Shortwave Thompson Grell-Freitas Ensemble 4.1.3 Identical to WRF-GFS except:
  • use topo_wind = 2, topographic surface wind correction from Mass
RCON NWS GFS Model YSU Noah-MP Revised MM5 Monin-Obukhov RRTMG Longwave and Shortwave Aerosol-aware Thompson Scheme Grell-Freitas Ensemble 4.1.3 Identical to WRF-GFS except:
  • Uses warm-rain modifications for the Thompson microphysics scheme from Robert Conrick
wrf4mynn NWS GFS Model Mellor-Yamada-Janjic TKE scheme Noah Monin-Obukhov (Janjic) scheme RRTMG Longwave and Shortwave Thompson Modifed Tiedtke 4.1.3 Uses the NCAR CONUS physics suite
tsno NWS GFS Model MYNN 2.5 level TKE Scheme Noah-MP old MM5 surface-layer scheme, option 91 RRTMG Longwave
Goddard Shortwave		 Aerosol-aware Thompson Scheme Grell-Freitas Ensemble modified 4.3.2 Code mods to Noah-MP to improve temperature cold bias over snow:
  • Use Verseghy (1991) snow thermal conductivity and limit to <= 0.25
  • Require deeper SNOWH (0.15 vs 0.05) in snow surface temperature and ground snow cover fraction calculations
  • Set snow depth and snow water equivalent to 0 for larger SNOWH values (1e-3 vs 1e-6) and SNEQV (1 vs 1e-3)
Preprocessing to limit effects of fresh snow on warm ground:
  • Set SNOWH, SNOW, SNOWC = 0 when top soil layer temperature exceeds 0C
stoc01
stoc02
stoc03		 NWS GFS Model YSU Noah-MP Revised MM5 Monin-Obukhov RRTMG Longwave and Shortwave Thompson Grell-Freitas Ensemble 4.1.3 Identical to WRF-GFS except:
  • no grid nudging for the 36-km domain, no FDDA
  • Use Stochastic Kinetic Energy Backscatter Scheme(SKEBS):
    A random pattern is used to perturb the potential temperature and rotational wind component. More information can be found here.
stoc04
stoc05
stoc06		 NWS GFS Model MYNN 2.5-level TKE Scheme RUC LSM MYNN Surface Layer RRTMG Longwave and Shortwave Aerosol-aware Thompson Scheme Grell-Freitas Ensemble 4.1.3 Identical to HRRR except:
  • Use Stochastic Kinetic Energy Backscatter Scheme(SKEBS):
    A random pattern is used to perturb the potential temperature and rotational wind component. More information can be found here.
Discontinued Ensemble Members
Member(s) Initializing Model PBL Land Surface Model Surface Layer Option Radiation Microphysics Cumulus WRF Code Version Other Parameters
wrfv75 NWS GFS Model YSU Noah-MP Revised MM5 Monin-Obukhov RRTMG Longwave and Shortwave Thompson Grell-Freitas Ensemble 4.1.3 Identical to WRF-GFS except:
  • 75 vertical levels instead of 38
  • Discontinued after the 2023020912 run