Page History

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• Sub-seasonal range ensemble (formerly extended range) forecast system:
  • The name of the extended range ensemble and associated forecast period is changed to sub-seasonal range ensemble and forecast period.  The forecast system itself is unchanged.
  • Unchanged are: 
    • the horizontal resolution remains at 36 km.
    • the vertical resolution remains at 137 model levels.
    • the number of ensemble members is 100 members plus a control member.
    • the sun-seasonal range ensemble is run daily from Day0 to Day46 based on 00UTC data.

• Wave model system:
  • the horizontal resolution is reduced to 9km for the medium range and to 36km for the sub-seasonal range. The resolutions are the same as the corresponding atmospheric model.
  • the number of medium range 2D wave spectra is reduced from 36 to 29. The first 29 frequencies in previous cycles are retained but the remaining 7 frequencies are not.
  • the wave model ensembles are run daily Day0 to Day15 based on 00UTC and 12UTC data and Day-0 to Day6 based on 06UTC and 18UTC data.
  • Unchanged are: 
    • the number of directions remains at 36. 

• Re-forecast systems for medium and sub-seasonal ranges:
  • increase in frequency; both are run over the past 20 years on fixed days of the month: 
    • Sub-seasonal range every two days: date in each month 1/3/5/7/9/11/13/15/17/19/21/23/25/27/29/31 (excluding 29 February).
    • Medium range every four days: date in each month 1/5/9/13/17/21/25/29 (excluding 29 February).

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