#!/bin/bash
#
# extract_grib2_pointdata.sh
#
# original script was coded by Takashi Unuma, Tsu local meteorological office, Japan Meteorological Agency
# last modified: 22nd July 2017
#
# requirements:
#  wgrib2, sed, awk (gawk is also available)
#

# specify grid point (x,y) of input file, which is able to obtain by typing as follows;
#  $ wgrib2 -llij [longitude] [latitude] grib2file
longrid=583
latgrid=561

# specify input grib2 file (for example, radar echo top data of JMA-RADAR)
infile=Z__C_RJTD_20140813150000_RDR_JMAGPV_Gll2p5km_Phhlv_ANAL_grib2.bin

# execute
# output data will be displayed in your terminal with the format of "YYYYMMDDHH (UTC) Echo top data [km]".
wgrib2 -ij ${longrid} ${latgrid} -s ${infile} 2> /dev/null | sed -e "s/\=/ /g" -e "s/:/ /g" | awk '{print $6,$4}'