Mark Konow, age 7, of Waynesville, N.C., for his question:

WHAT IS HAIL?

Hail is round, hard balls of ice that fall from clouds during thunderstorms. Hail can measure from the size of a small pea to a baseball. A record hailstone measuring 17 1/2 inches and weighing almost two pounds fell during a storm in Coffeyville, Kan., in 1970. Large stones, as you can well imagine, can cause serious damage to crops, animals and people.

Hail falls most often in spring.

Hailstones have an onion like structure, with a number of layers of ice. They form much as sleet does. When snowflakes or small ice crystals strike supercooled water drops, the water freezes instantly. During its fall, a hailstone can receive many layers of ice.