But those categorical threat levels are imperfect and can lead to confusion, as well, Carbin said. The “slight risk” category was meant to explain that a chance for severe weather existed, but the storm was too scattershot or isolated to predict with much certainty which towns or neighborhoods would be affected, he said. So a thunderstorm or tornado would occasionally take residents by surprise on “slight risk” days.
“The word ‘slight’ doesn’t convey the right message when it comes to severe weather,” he said. “What we want to do is better define that ‘slight’ in terms of risk.”