Mary Morelle, age 10, of Utica, New York, for her question:

How can it hail on a hot day?

The world of weather is up there in the air    and what goes on up there may be very different from what is going on at ground level. On a hot summer day, the ground level temperature may soar to a seething 90 degrees Fahrenheit. At the same time, up there a few miles above the surface, the air may be cold enough to freeze water. This is most likely to happen when a stormy thunderhead piles up overhead. That cloud is a turbulent mixture of air masses    warm and cool, damp and dry.

Its wild winds blow up and down and in all directions. Hailstones form when moist, warmish raindrops get whisked through pockets of cold, dry air. The liquid moisture is frozen into solid pellets of ice. The hail pellets grow bigger as they are tossed back and forth between different parts of the thunderhead. And, while all this icy hail is freezing on high, the ground below remains scorching hot. When the pellets of hail become too heavy to be tossed back and forth within the thunderhead, they fall, regardless of how hot it is below.