What Does Jackie Purcell Use to Forecast the Weather?

There are hundreds of instruments forecasters use to predict weather. They range from simple, like the wind vane, to hi-tech, like the weather balloon.

Some instruments are very simple. For example, the wind vane is not new technology but it is extremely useful. A wind vane points to the direction the wind is coming from. It is made up of a thin, flat pointer and a slightly larger fin. These are connected to a horizontal pole that has a vertical rod sticking down through it, so the pointers and pole can rotate freely on the rod. A barometer is also a very simple instrument, but again very useful. It senses air pressure. The way in which it does this depends on the barometer. A mercury barometer is a glass tube of liquid (usually mercury) that expands when the air pressure is low and moves up the tube. When the pressure is high, the mercury contracts and moves back down the tube. An aneroid barometer is a small, airtight, metal container that has slightly flexible sides. The sides flex in when the air pressure is high, and out when it is low. A dial shows how much the walls are flexing. Both types of barometers are very accurate and extremely useful. Wind vanes and barometers are very simple but amazingly useful.

Also, there are very sophisticated instruments that involve the latest technology. Satellites and weather balloons, for example, are just that. Satellites take pictures of the Earth and its cloud formations from different places in the atmosphere. The pictures are then beamed wirelessly down to the Earth to be seen and printed off of computers. You may have seen some pictures of tornadoes or hurricanes that were taken from satellites. Weather balloons are also amazing technology. A balloon carries a small package of instruments up into the atmosphere. On the way up, the instruments take readings and record them. Soon, the pressure is low outside the balloon, but very high inside and the balloon breaks. The package of instruments falls down to Earth, where scientists find it and record the data. This new technology helps scientists in many ways and is being improved even more every day.

As you can see, these are just a few of the many instruments forecasters use to predict weather. They send their predictions to many people and it is especially valuable to transporters so that they can make sure the weather is good when they plan to move things. The scientists use both high and low technology, but it is all valuable to everyone.