An old saying used for forecasting (预测) the weather says, "Red sky at night, sailors' delight. Red sky in the morning, sailors (水手) take warning. " Is the saying true? It turns out that it is. A red sky at sunset may mean that there are clear skies to the west, where the sun sets. A red sky at sunrise usually means that the clear weather has already passed, so storms might be coming.
Forecasting the weather has been practiced for thousands of years. In the 5th century BC, the Greeks sent out forecasts to sailors. They used signs in nature to forecast the weather. But today, meteorologistssend exact forecasts further in advance (提前). They use scientific instruments to study weather conditions around the world and make forecasts. Pilots, farmers and many other people depend on these forecasts. Luckily, most of us can simply look on the smart phone or turn on the TV to find out what kind of weather is coming.
If you are looking for some signs of the weather, pay attention to nature. There are two basic rules used in weather forecasting: Weather generally moves from west to east, and low air pressure (压力) usually means rain or snow. So pay attention to the signs. If rainbows form in the west at sunrise, the sun is on the way. Smell the flowers—their smells are stronger in wet air. What are the ants doing? Are they moving to higher ground? This could mean a drop in air pressure. Are the birds flying low or high? Falling air pressure may influence birds' ears, so they fly low. And if the sky is red at sunset, you might plan a picnic for the next day!
