[SOLVED] Recent Pygrib fail to retrieve ecmwf grib2 data within latitude and longitude

Recent Pygrib fail to retrieve ecmwf grib2 data within latitude and longitude

Previously I had no problem to retrieve rainfall data from real-time forecast ecmwf using this command;

1    import pygrib
2    import numpy as np
3    
4    source='./10-Download-ECMWF/'
5    grbs = pygrib.open(source+'10-data.grib2')  
6    grb2 = grbs.message(1) ### message start from 1, message 1=rainfall, mesage2=temp    
7    data, lats, lons = grb2.data(lat1=-10, lat2=20, lon1=90, lon2=130)

Old data downloaded in my archive still can be used but after new download in June 2023 onwards the problem begins and showing this messages;

RuntimeError: b'Function not yet implemented'  #### the problem mentioned at line 7

Anyone got ideas?. Thanks in advance.

Solution

first of all try to upgrade your pygrib

pip install --upgrade pygrib

and if the issue persists,

you can try another alternative library called pygrib2, so first install this :

pip install ecmwf-api-client

and now

from ecmwfapi import ECMWFDataServer
import pygrib2

# ECMWF API credentials
server = ECMWFDataServer(url="https://api.ecmwf.int/v1")

# parameters for data retrieval
dataset = "cams_gfas"
date = "2023-06-01/to/2023-06-30"
time = "00:00/06:00/12:00/18:00"
area = "10/-10/20/130"
target = "output.grib"

# retrieve the GRIB file
server.retrieve({
    "dataset": dataset,
    "date": date,
    "time": time,
    "area": area,
    "target": target,
    "format": "grib"
})

#open the downloaded GRIB file and retrieve the rainfall data, latitude, and longitude values
grbs = pygrib2.open("output.grib")
grb = grbs[1]  # Assuming rainfall is in the first message
data = grb.values
lats, lons = grb.latlons()

#use the retrieved data as needed
print(data)
print(lats)
print(lons)

good luck !