Warning policy

Warning-issue threshold: 0.55

This case study models 500 forecast days, each with a model-estimated probability of severe weather. Issuing a warning at a low threshold catches nearly every real severe weather event, but also issues many warnings on days that turn out calm — eroding public trust in future warnings.

Season outcome

Warnings issued—

True severe-weather events caught—

False-alarm warnings—

Forecast days by severe-weather probability (blue = warning issued, ring = true severe event)