Extreme Forecast Index (EFI) & Shift of Tails (SOT)
Potentially extreme weather can be identified with the powerful tools EFI and SOT. These indices provide ensemble-based measures of how likely and how extreme a weather event would be than usual, given as likelihood measure (not probability for a certain event).
efi: Extreme Forecast Index
sot: Shift Of Tails.
Both types of parameters are based on the Cumulative Distribution Function of the different models that make up the ensemble and refer to a certain time range over which they measure the tendency for extreme events. EFI values over 0.8 denote high likelihood for unusual conditions. SOT values signify their extremeness. Only for temperature, the shift of distribution tails is given for both the upper (default) and the lower tail (marked additionally).
Selection of time interval
These indices are queried together with a time range which they are valid for, i.e. t_2m_1d_efi:idx. Date/time stamps are right aligned.