THE AREA OBSERVED DECAYS LOGARITHMICALLY AS THRESHOLDS INCREASE
THE ACCURACY OF FORECASTS ALSO DECAYS LOGARITHMICALLY EXCEPT FOR THE VERY HIGHEST THRESHOLDS
Because higher amounts or thresholds are relatively rare,
it is difficult
getting a big enough sample to calibrate forecasts using traditional
statistical techniques. Verification of 24 hour QPF for various
thresholds
A LOG LINEAR DECAY IN OBSERVED AREA OF PRECIPITATION AND IN HPC THREAT SCORES
25
50
25
75
100
mm
50
75
100
mm