GoalDescribe how a weather forecast is made from measurements taken in many places and at many times.
New words
meteorology · the science that studies the weather and works out what it will do nextforecast · a prediction of the weather to comedata · measurements and facts that we collect
Explanation
A weather forecast is a careful prediction, not a guess. Meteorology is the science that studies the weather. A meteorologist, a weather scientist, first collects data: temperature, wind, rain, humidity (how much water vapour is in the air) and air pressure (how hard the air pushes). The data come from many places and many times, because the weather in one town is linked to the weather around it. Next the data are put on maps and in tables so that patterns can be seen. Then the scientist, often with a computer, predicts what will happen. A good forecast says what will probably happen. It is never one hundred percent sure, so it is wise to listen for updates.
collect data→show it on charts→find patterns→make a forecast→update it
Worked examples
Salma’s father is a farmer. Before he waters the field he checks the forecast, because rain may come tomorrow and save water.
Day
Temperature at 8 a.m.
Sat
22
Sun
23
Mon
24
Tue
25
Youssef records the temperature at 8 a.m. for four days. He sees the days getting a little warmer, and can say the next day is likely to be warm too.
A weather scientist in Cairo cannot forecast Aswan with only Cairo’s data. She needs measurements from many places.
Class activity
Be a forecaster. For three days at the same time, a grown-up and you read the temperature outdoors and note the sky and wind. Then predict tomorrow and check. Were you right? Never look at the Sun. A forecast is only a prediction.
Practice
1
What is meteorology?
The science that studies the weather and works out what is coming.
2
Name two kinds of data a forecaster collects.
For example temperature, wind, rain, humidity or air pressure.
3
Why do forecasters collect data from many places?
Weather in one place is linked to weather around it.
