In a weather forecast, how is it determined to describe upcoming storms as severe versus strong?
Thunderstorms occur at many levels of intensity, from brief summer storms to violent, deadly ones that disrupt life and destroy property. To help the public anticipate what kind of thunderstorm to expect, the National Weather Service has instituted definitions to portray the strength and severity of the approaching storm. A severe thunderstorm produces one or more of the following: a tornado; winds of 58 m.p.h. or higher; hail one-inch in diameter or larger. Strong thunderstorms are those whose vigor approaches but does not achieve those severe criteria. Lighting and flood-producing rainfall, phenomena that can cause great damage and death, are not included in the criteria for severe thunderstorms.