Hail can act as an indicator of severe weather and possibly tornadoes. The National Weather Service does not even classify a storm as severe unless one of three conditions are met. The storm must have

• Hail larger than the size of a penny
OR
• Damaging wind gusts in excess of 58 mph
OR
• Tornadoes

This week, hail, high winds, and severe thunderstorms ripped across at least 4 states killing at least 7 people. (Read the full story on the storms from CNN)