Split JMA one-week ensemble using wgrib

splitwfm

#!/bin/bash
N=25 # number of ensembles
NFT0=9 # number of forecast time (including FT=0)
NFT=9
VNAME=""
while getopts ":v:n:" opt; do
  case $opt in
    v)  VNAME=$OPTARG ;;
    n)  NFT=$OPTARG ;;
    \?) echo 'usage:: splitwfm [-v VARNAME -n NFT] FNAME'
        exit 1
  esac
done
shift $(($OPTIND-1))
FNAME=$1
if [ -z "$FNAME" ]; then
  echo 'usage:: splitwfm [-v VARNAME -n NFT] FNAME'
  exit 1
fi
ONAME=`basename $FNAME`
case $ONAME in
  WFM12*PLL) NVAR=5 ;;
  *) NVAR=4 ;;
esac
echo $ONAME $NVAR
I=1
while ((I<=N)); do
  II=`printf %0.2i $I`
  if [[ -n $VNAME ]]; then
    wgrib $FNAME | grep $VNAME | head -$((NFT0*(I-1)+NFT)) | tail -$NFT |  wgrib $FNAME -i -grib -o ${ONAME}_$II.grb
  else
    wgrib $FNAME | head -$((NFT0*NVAR*(I-1)+NFT*NVAR)) | tail -$((NFT*NVAR)) |  wgrib $FNAME -i -grib -o ${ONAME}_$II.grb
  fi
  ((I=I+1))
done