Starting today, the criteria to reach the threshold for a severe thunderstorm has changed. Research has showed that hail, flooding, high winds, and tornadoes cause extensive damage to homes and property. However, recent studies about hail size governs the lower limit of identifying a thunderstorm as severe.

Here is the old definition of a severe thunderstorm. A thunderstorm needs to reach one of these three criteria in order to become severe.

-Constant wind gusts of 58 mph or higher.

-Hail diameter of 3/4 of an inch or greater.

-Formation of a tornado.

Notice that rain rates or lightening strokes are not within the criteria. Now with the completion of research about hail size and damage, the new criteria only changes the size of hail. Now, in order for a thunderstorm to be considered to be severe, it can either reach the wind limit, form a tornado and/or create hail at a diameter of 1 inch or greater.

This means that storms will have a harder time being considered severe, and warnings would not issued as often. Research on hail discovered that hail with a diameter of 1 inch has the ability to create substantially more damage then hail with a diameter of 3/4 or less.

Print this Story