nwp-python-jul-2021/script_03.py at main · diegormsouza/nwp-python-jul-2021 · GitHub

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#----------------------------------------------------------------------------------------------------------------------
# INPE / CPTEC Training: NWP Data Processing With Python - Script 3: Basic Operation / Color Palettes / Colorbar / Title / Date
# Author: Diego Souza
#----------------------------------------------------------------------------------------------------------------------
import pygrib                   # Provides a high-level interface to the ECWMF ECCODES C library for reading GRIB files
import matplotlib.pyplot as plt # Plotting library
#----------------------------------------------------------------------------------------------------------------------

# Open the GRIB file
grib = pygrib.open("gfs.t00z.pgrb2full.0p50.f000")

# Select the variable
grb = grib.select(name='2 metre temperature')[0]

# Get information from the file
init  = str(grb.analDate)      # Init date / time
run   = str(grb.hour).zfill(2) # Run
ftime = str(grb.forecastTime)  # Forecast hour
valid = str(grb.validDate)     # Valid date / time
print('Init: ' + init + ' UTC')
print('Run: ' + run + 'Z')
print('Forecast: +' + ftime)
print('Valid: ' + valid + ' UTC')

# Select the extent [min. lon, min. lat, max. lon, max. lat]
extent = [-93.0, -60.00, -25.00, 18.00]

# Read the data for a specific region
tmtmp, lats, lons = grb.data(lat1=extent[1],lat2=extent[3],lon1=extent[0]+360,lon2=extent[2]+360)

#----------------------------------------------------------------------------------------------------------------------
# Convert from K to °C
tmtmp = tmtmp - 273.15

#----------------------------------------------------------------------------------------------------------------------
# Choose the plot size (width x height, in inches)
plt.figure(figsize=(8,8))

# Plot the image
plt.imshow(tmtmp, origin='lower', cmap='nipy_spectral')

# Add a colorbar
plt.colorbar(label='2 m Temperature (°C)', extend='both', orientation='horizontal', pad=0.05, fraction=0.05)

# Add a title
plt.title('GFS: 2 m Temperature' , fontweight='bold', fontsize=10, loc='left')
plt.title('Valid: ' + valid, fontsize=10, loc='right')
#-----------------------------------------------------------------------------------------------------------
# Save the image
plt.savefig('image_3.png')

# Show the image
plt.show()