High-Resolution Ensemble Forecast

HREF

The NCEP High-Resolution Window Forecast System (HIRESW) consists of daily runs of the regional version of the Finite Volume Cubed Sphere (FV3) model and two NCAR Advanced Research WRF (WRF-ARW) runs at ~3 km resolution. Currently, five domains are being run, two large domains (CONUS, Alaska) and three small domains (Hawaii, Puerto Rico, and Guam). The second ARW run (ARW2) is not run over Guam. The source of each run's initial (IC) and boundary conditions (BC) follows:

  1. Alaska FV3/ARW1 : IC/BC from 6-h old GFS
  2. Alaska ARW2 : IC from current NAM, BC from 6-h old NAM
  3. CONUS FV3 : IC/BC from 6-h GFS
  4. CONUS ARW1 : IC from current RAP, BC from 6-h old GFS
  5. CONUS ARW2 ; IC from current NAM, BC from 6-h old NAM
  6. Hawaii FV3/ARW1: IC/BC from 6-h old GFS
  7. Hawaii ARW2 : IC from current NAM, BC from 6-h old NAM
  8. Puerto Rico FV3: IC/BC from 6-h old GFS
  9. Puerto Rico ARW1: IC from current RAP, BC from 6-h old GFS
  10. Puerto Rico ARW2: IC from current NAM, BC from 6-h old NAM
  11. Guam FV3/ARW1 : IC/BC from 6-h old GFS

These are the forecast initial times at which the respective HIRESW domains are run:

- 0000 and 1200 UTC : CONUS, Hawaii, Guam

- 0600 and 1800 UTC : Alaska, Puerto Rico

The NCEP High-resolution Ensemble Forecast system (HREF) aggregates existing deterministic convection-allowing forecasts to create ensemble products. HREF uses current and time-lagged forecasts from the HiresWindow run (ARW/FV3 over CONUS, Alaska, Hawaii, Puerto Rico). For the CONUS domain, the 3km HRRR and 3 km NAM nest is also used. For the Alaska domain, the 3 km HRRR is also used as a member. HREF is a precursor to a unified high-resolution ensemble forecast system, the Rapid Refresh Forecast System (RRFS), which will be constructed around the UFS and utilizing the FV3 dynamical model.

The latest graphics generated by EMC for the CONUS, Alaska, Hawaii, and Puerto Rico are accessible at the HREF home page.

For more info on the HREF and the HiresW, please contact Matthew Pyle

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