Weather

Many people really do need to know the weather forecast. Farmers, for example, need to know if it will rain tomorrow so that they can decide whether or not to water their crops. Sailors need to know if it will be safe to sail out to sea the following day. Airplane pilots need to know if their flight path will be clear or stormy. You also need to know – if only to plan your activities for tomorrow.

Questions and answers

How far ahead can we predict the weather?

We are getting better and better at predicting the weather. A five-day weather forecast today is generally as reliable as a two-day forecast twenty years ago. Information is now transferred worldwide within hours, and phenomena that affect long-term “weather” or seasonal climate such as El Niño can be forecast several seasons in advance. The more we understand the interactions between the oceans and the atmosphere, the better we can predict weather and climate.

Will we ever be able to control weather in the future?

Experiments continue on what we call “weather modification.” One of these experiments, “cloud seeding,” was first tested in 1946. Cloud seeding is the attempt to change the amount of rain produced by clouds by targeting clouds from aircraft or from the ground with substances such as silver iodide, dry ice and even salt. In the 1950s and 1960s, American scientists conducted research under the name “Project Stormfury” to modify tropical cyclones, but the research was inconclusive.

Today, cloud seeding is used in several countries to attempt to increase the amount of rain in areas affected by drought; to reduce the size of hailstones that form in thunderstorms; and even to provoke snow in mountains at major ski resorts. We cannot say, however, that we are able to control the weather, and weather modification remains an area of active research in many countries.

Facts about weather and climate