Cathleen Murrell., Age 13, Of Portland, Ore., For her question:

What causes an updraft wind?

Warm air expands and spreads out to take more space. When the sun shines, some Patches of the earth get more heat than others, and the air gets its heat from the Ground or the sea below it. A warmed patch of air tends to expand in all directions, but sometimes it is surrounded on all sides by cooler air which refuses to move. When this happens, there is only one direction for the expanding air to go. It Must go up. It becomes an updraft, a current of warm air rising frown the surface of the earth.