def get_theta_from_grb(DATE):
"""
Gets the potential temperature at a point from the HRRR surface field
files for a single time.
"""
VALID_DATE = DATE + timedelta(hours=fxx)
DIR = '/uufs/chpc.utah.edu/common/home/horel-group/archive/%04d%02d%02d/models/' % (
DATE.year, DATE.month, DATE.day)
# Open HRRR and get surface temperature and surface pressure
grbs = pygrib.open(DIR + 'hrrr/hrrr.t%02dz.wrfsfcf%02d.grib2' %
(DATE.hour, fxx))
temp = grbs.select(name="2 metre temperature")[0].values[
subset[domain][0]:subset[domain][1],
subset[domain][2]:subset[domain][3]] - 273.15
sfcpres = grbs.select(name="Surface pressure")[0].values[
subset[domain][0]:subset[domain][1],
subset[domain][2]:subset[domain][3]] / 100
lat, lon = grbs.select(name="2 metre temperature")[0].latlons()
lat = lat[subset[domain][0]:subset[domain][1],
subset[domain][2]:subset[domain][3]]
lon = lon[subset[domain][0]:subset[domain][1],
subset[domain][2]:subset[domain][3]]
# Get the 700 hPa temperatures
T700 = grbs.select(name="Temperature")[1].values[
subset[domain][0]:subset[domain][1],
subset[domain][2]:subset[domain][3]] - 273.15
# Convert temperatures to potental temperature (theta)
theta_sfc = TempPress_to_PotTemp(temp, sfcpres)
theta_700 = TempPress_to_PotTemp(T700, 700)
# Pluck value for the station location
pluck_index = pluck_point(stn_lat, stn_lon, lat, lon)
# use that pluck index on the flattened array to ge the value
stn_theta_sfc = theta_sfc.flatten()[pluck_index]
stn_theta_700 = theta_700.flatten()[pluck_index]
# Return the values
print "Got it:", DATE
# close the grib file
grbs.close()
return [VALID_DATE, stn_theta_sfc, stn_theta_700]
def plot_excess_temp_map(input):
DATE = input - timedelta(hours=12)
date = DATE.strftime('%Y-%m-%d_%H%M')
print 'working on', date
DIR = '/uufs/chpc.utah.edu/common/home/horel-group/archive/%04d%02d%02d/models/' % (
DATE.year, DATE.month, DATE.day)
# Open HRRR and get surface temperature and surface pressure
grbs = pygrib.open(DIR + 'hrrr/hrrr.t%02dz.wrfsfcf12.grib2' % (DATE.hour))
temp = grbs.select(name="2 metre temperature")[0].values[
subset[domain][0]:subset[domain][1],
subset[domain][2]:subset[domain][3]] - 273.15
sfcpres = grbs.select(name="Surface pressure")[0].values[
subset[domain][0]:subset[domain][1],
subset[domain][2]:subset[domain][3]] / 100
lat, lon = grbs.select(name="2 metre temperature")[0].latlons()
lat = lat[subset[domain][0]:subset[domain][1],
subset[domain][2]:subset[domain][3]]
lon = lon[subset[domain][0]:subset[domain][1],
subset[domain][2]:subset[domain][3]]
# Get the 700 hPa temperatures
T700 = grbs.select(name="Temperature")[1].values[
subset[domain][0]:subset[domain][1],
subset[domain][2]:subset[domain][3]] - 273.15
# Convert temperatures to potental temperature (theta)
theta_sfc = TempPress_to_PotTemp(temp, sfcpres)
theta_700 = TempPress_to_PotTemp(T700, 700)
# pluck the value for SLC
SLC_lat = 40.77
SLC_lon = -111.95
pluck_index = pluck_point(SLC_lat, SLC_lon, lat, lon)
# use that pluck index on the flattened array to ge the value
SLC_sfc_temp = temp.flatten()[pluck_index]
SLC_sfc_theta = theta_sfc.flatten()[pluck_index]
SLC_700_temp = T700.flatten()[pluck_index]
SLC_700_theta = theta_700.flatten()[pluck_index]
return [SLC_sfc_temp, SLC_sfc_theta, SLC_700_temp, SLC_700_theta]