1Every morning, meteorologists around the world begin their day by studying the sky.
2Weather balloons rise high into the atmosphere and measure temperature, wind, and humidity.
3Satellites far above the earth send back pictures of huge moving cloud systems.
4Powerful computers compare all this information with records from many past years.
5The computers then predict where the clouds and rain will probably travel next.
6Because the air is always changing, forecasts become less certain after several days.
7A small shift in wind direction can push a storm far off course.
8That is why a sunny promise sometimes ends with an unexpected shower.
9Forecasters study the newest satellite images again just before they speak on television.
10Their early warnings help farmers protect crops and sailors avoid dangerous waves.
11Thanks to science, we can prepare for weather that once surprised everyone.