Data Assimilation System (go here for realtime analysis system statistics, changes on May 2, 2016)
  • WRF-ARW V3.6.1 + NCAR Data Assimilation Research Testbed (DART) Modified: RMA branch
  • Continuously-cycled ensemble adjustment Kalman filter (EAKF)
  • Modified: 80 ensemble members (50 members prior to 2 May 2016)
  • New analysis every 6-hrs
  • 15-km horizontal grid spacing
  • 40 vertical levels with a 50 hPa top
  • Horizontal localization: 1270 km
  • Vertical localization: 1.5 scale heights
  • Adaptive prior inflation
  • Adaptive localization
  • Sampling error correction
  • NEW: Spread restoration
  • Freely-evolving soil states (since mid-March 2015)
  • Observations: MADIS ACARS, METAR, PROFILER, RADIOSONDE; NCEP MARINE; CIMMS cloud-track winds; Oklahoma mesonet; NEW: GPS radio occultation
  • Single-physics ensemble:
    • Tiedtke cumulus parameterization
    • Thompson microphysics parameterization
    • MYJ PBL scheme
    • NOAH land-surface model
    • RRTMG shortwave and longwave radiation with aerosol and ozone climatologies
Ensemble Forecast System (homepage)
  • WRF-ARW V3.6.1 forecasts initialized daily at 0000 UTC
  • 10 ensemble members
  • 3-km horizontal grid spacing
  • 48-hour forecasts
  • Initial conditions provided by downscaled members of 0000 UTC WRF/DART EAKF analyses (above)
  • Perturbed lateral boundary conditions originating from GFS forecasts
  • Physics same as data assimilation system (above) without cumulus parameterization
  • Diagnostics generated from WRF-ARW and Unified Post Processor (UPP) output
  • NEW: Updates to Thompson/Hailcast diagnostics
NCAR Ensemble Development Team

Kate Fossell, Glen Romine, Craig Schwartz, Ryan Sobash


Davide Del Vento (NCAR/CISL), Ryan Torn (University of Albany), Greg Thompson (NCAR/RAL), Stan Trier (NCAR/MMM), Morris Weisman (NCAR/MMM), Dave Ahijevych (NCAR/MMM), Michael Coniglio (NOAA/NSSL), Kent Knopfmeier (OU/CIMMS), NSSL, Storm Prediction Center

External Support

NOAA HWT award NA15OAR4590191: These environmental data and related items of information have not been formally disseminated by NOAA and do not represent and should not be construed to represent any agency determination, view, or policy.


ensemble AT ucar DOT edu