Here is a simple code to generate synthetic time series.
import numpy as np
import pandas as pd
med = 15.5
dp = 8.2
sDays = np.arange('2001-01', '2016-12', dtype='datetime64[D]')
nDays = len(sDays)
s1 = np.random.gumbel(loc=med,scale=dp,size=nDays)
s1[s1 < 0] = 0
dfSint = pd.DataFrame({'Q':s1},index=sDays)
dfSint.plot()