Here is another example where ProbSevere rapidly increased form 18% to 94% (click image to animate):

The normalized vertical growth rate and the glaciation rate were both strong. In this case, I was confident enough to use the ProbSevere by itself to issue a severe thunderstorm warning. I started drawing the warning polygon prior to the highest percentage coming from ProbSevere. In the end, my polygon was issued nearly coincident with the highest probabilities.

Polarimetric Researcher