HOW DOES THE WEATHERMAN KNOW WHAT TO SAY

HOW DOES THE WEATHERMAN KNOW WHAT TO SAY?
All the conditions of the atmosphere are ''weather.'' Whether it's hot or cold, dry or wet, sunny or cloudy, windy or still, it's ''weather.'' The weather is changeable from day to day, and the total effect during a year is called ''the climate.''
There are many complicated reasons for changes in the weather, but the most important influence is the sun. The sun's heat evaporates water and warms the air, so that rising currents of warm air carry water vapor into the sky. There the air cools and the vapor condenses into rain. These things happen gently or violently. When they take place violently, we have storms.
In great Britain there are approximately 200 weather reporting stations and roughly the same number spread over the rest of Europe. In addition, ''weather ships'' stationed in the Atlantic and special aircraft on regular patrol send back systematic reports on weather conditions. From this and other meteorological data weather forecasts are produced.
The maps which the weather experts srudy show them many things: places where the air pressure is equal,