import Nio
from mpl_toolkits.basemap import Basemap
import matplotlib.pyplot as plt
import numpy as np
f = Nio.open_file('nww3.t00z.grib.grib2')
print f.variables.keys()
lons = f.variables['lon_0'][:]
# flip latitudes so data goes S-->N
lats = f.variables['lat_0'][::-1]
times = f.variables['forecast_time0'][:]
datavar = f.variables['HTSGW_P0_L1_GLL0']
"""ntime=10=30hrs"""
ntime = 5
data = datavar[ntime,::-1]


lons[0] = -33.00
lats[0] = 42.00

lons[2] = 10.00
lats[2] = 65.00

fig = plt.figure(figsize=(16,16))

m = Basemap(projection='cass',lon_0=-6,lat_0=54.5,\

            llcrnrlat=lats[0],urcrnrlat=lats[2],\
            llcrnrlon=lons[0],urcrnrlon=lons[2],\
           rsphere=6371200.,resolution='i',area_thresh=1)
x, y = m(*np.meshgrid(lons, lats))
levels = np.arange(0,9.1,0.5)
m.fillcontinents(color='#477519')
m.drawcoastlines(linewidth=0.5, color='k', antialiased=1, ax=None, zorder=None )
m.contourf(x,y,data,levels)
#m.drawparallels(np.arange(40,81,10),labels=[1,0,0,0])
#m.drawmeridians(np.arange(150,241,10),labels=[0,0,0,1])
#m.drawparallels(np.arange(40,81,10),labels=[1,0,0,0])
#m.drawmeridians(np.arange(150,241,10),labels=[0,0,0,1])
plt.title(datavar.long_name+' %s hr fcst'%(times[ntime]),fontsize=12)
plt.colorbar(orientation='horizontal',shrink=0.9,format="%g")
plt.show()