James Kramer, age l0, of Fowler, Mich., for his question:

Why are some snowflakes hard and some soft?

The formation of snowflakes is a very tricky weather event. There are so many fine processes that one wonders how the atmosphere manages to make snowflakes at all. We know part of the story, but experts are still studying the fine details in their laboratories. snowflakes are formed from gaseous water vapor in the air. And the slightest change in temperature or in the amount of vapor makes a difference in their formation.

The air must be chilly enough to change gaseous molecules of water vapor into crystals of ice. Warm air tends to hold more vapor and when the temperature is just below freezing there are plenty of new ice crystals. They bunch together to make big, soft and fluffy snowflakes. In colder air with less vapor there are fewer crystals and the job is not so easy. The fine crystals tend to form hard little flakes like frozen pellets.