EMC: Info on the Ensemble forecasts using the Global Spectral Model
At NCEP the current NCEP Global Ensemble configuration consists
of runs:
At 00Z, 06Z, 12Z 18Z each day (available through anonymous ftp from public servers):
-
T382L64 high resolution control (file name for, e.g., a 24 hr fcst at 00Z is: gfs.t00z.pgrbf24)
out to 7 days, after which this run gets truncated and is run out to 16
days at a T126L64 resolution
-
T126L28 control that is started with a truncated T382L64 analysis, run out to 16 days. gec00.t00z.pgrb(a/b)f24
-
20 perturbed forecasts each run out to 16 days at T126L28 horizontal and vertical resolution. The perturbations
are from Ensemble Transform (ET) with rescaling (See Wei and etc. 2007:Initial perturbations based on the ensemble transform
(ET) technique in the NCEP global operational forecast system, Tellus)
Each perturbated forecastd will be: gep(01/02/03...).t00z.pgrb(a/b)f24,
The examples of files given above are pressure grib files, containing also
flux and surface related fields. For information and software on how to
read grib format files, using different platforms, click
here . If you have questions regarding the ensemble forecasts you can contact:
Yuejian Zhu at Yuejian.Zhu@noaa.gov
