Download grib files from noaa.gov. Will only work every hour a new forecast is published.

gribdown.sh

#!/usr/bin/env bash

urldate=`date +%Y%m%d%H`

mkdir  -p "data/gfs/$urldate"
cd  "data/gfs/$urldate"

for no in `seq -f "%03g" 0 3 30`;
do
    echo " Fetching log for date $urldate, no $no"
    wget "http://www.ftp.ncep.noaa.gov/data/nccf/com/gfs/prod/gfs.$urldate/gfs.t00z.pgrb2.2p50.f$no"
done