Ensemble GRIBs decoding

[Mandelli Alessandro]

I would like to make use of the gribs found in
ftp://ftpprd.ncep.noaa.gov/pub/data/nccf/com/mrf/prod/

I downloaded enspost.t00z.z500 and the index file enspost.t00z.z500i

Then I created the control file
ga-> !perl grib2ctl.pl -verf enspost.t00z.z500 enspost.t00z.z500i
 >enspost.ctl

Result is

dset ^enspost.t00z.z500
index ^enspost.t00z.z500i
undef 9.999E+20
title enspost.t00z.z500
*  produced by grib2ctl v0.9.12.5p33j beta11
dtype grib 2
options yrev
ydef 73 linear -90.000000 2.5
xdef 144 linear 0.000000 2.500000
tdef 65 linear 00Z22jan2005 6hr
zdef 1 linear 1 1
vars 1
HGTprs  0 7,100,500  ** Geopotential height [gpm]
ENDVARS

I just modified "zdef 1 linear 500 500" for consistency.

Then I mapped the grib

ga->!gribmap -i enspost.ctl

So far so good. I'm proudly plotting all timesteps of the variable.
Fact is that I'm pretty sure that in the grib all 12 members for the 65
timsteps are included.
In fact
ga-> !wgrib -v enspost.t00z.z500

gives fcst+0, -0, +1, -1, etc. for all the 12 members.
Unfortunately I'm not able to extract the members from the grib.
Anyone has a control file or a suggestion how to do it?

Thanks
Regards