# How to calculate Lifted Index from ERA5 pressure level data?

I have taken a thunderstorm case where I need to calculate indices but I am not getting any code related stability indices in Python language, the code is available in GRADS, NCL for me it's difficult to understand. I used MetPy code but they are not calculated LI, KI, and other indices...Thanks in advance Below code is wrong that I know I used the formula but tell me the correct way.

nc1=Dataset('pl_120415.nc')
lat1=np.array(nc1.variables['latitude'])
lon1= np.array(nc1.variables['longitude'])
lev= np.array(nc1.variables['level'])
time= nc1.variables['time']
r= nc1.variables['r'][:,:,25:28,20:25]
t= nc1.variables['t']
u= nc1.variables['u'][:,:,25:28,20:25]
v= nc1.variables['v'][:]
w= nc1.variables['w']

t_500= nc1.variables['t'][:,21,:,:] ### domain Air Temperture  at 500 Pressure_level
tp_500= nc1.variables['t'][:,21,25:28,20:25] ## at specfific location temperature (parcel temperture)

li=np.subtract(t_500,tp_500,dtype=np.float32)

print("LI",li)

• Hi, welcome to Stackexchange. Some may argue that this is off-topic here. I'd say it is on topic, but you'll need to be a lot clearer in explaining exactly what you're trying to do, and what you don't understand. "I need to calculate indices" doesn't tell me very much! What indices? Jul 9, 2019 at 16:49
• @SemidiurnalSimon thanks fo reply. Can you open this link weather.cod.edu/sirvatka/si.html . You may understand my query. Jul 10, 2019 at 4:18

Metpy 1.0 has a lifted_index function, which requires a profile temperature parameter, which in turn can be calculated using the parcel_profile function. That requires having the dew point temperature, which you would either have to have directly, or calculate from another moisture content variable. I'm not sure what your r variable is, so I'm not sure whether that could help you with such a calculation. Also, rather than using numpy arrays, using xarray for working with netcdf input variables tends to be easier and more efficient.