What is a Weather Balloon?
A weather balloon is a scientific instrument which is used to collect data about atmospheric weather conditions. Some people also call weather balloons “sounding balloons,” because they take soundings of the atmosphere. This data is used in weather prediction, and to track general weather trends. Numerous agencies all over the world release weather balloons on a daily basis, and they generally share the information collected, in the interest of scientific cooperation. A basic weather balloon will collect information about the ambient temperature, atmospheric pressure, and humidity. Typically, this information will be gathered during the ascent of the weather balloon and while it is hovering at altitude. The data is sent back to Earth with transponders. A weather balloon may also be used to collect information about wind speed and patterns, by transmitting its geographic location back to Earth. The package of instruments in a weather balloon is called a radiosonde. The earliest radioson
When snow or rain falls into dry air it can evaporate on the way down and none hits the ground. For rain and snow this is called virga. Radar “sees” rain or snow falling. Meteorologists can tell where it’s not reaching the ground when weather stations in the area do not report any snow or rain hitting the ground where radar shows it’s falling. A USATODAY.com graphic shows how Dry air causes invisible rain. (It works the same for snow and rain.) Twice a day, weather stations around the world send up balloons, filled with helium or hydrogen, with packages of weather measuring instruments attached. As the balloon rises, a radio sends back the data being recorded by the instruments. The balloon’s direction and speed are tracked and radioed back, giving information about wind speeds and directions at the different altitudes. This data is important for weather forecasts. A graphic on how weather balloons work will tell you more. (Answered by Jack Williams, USATODAY.com weather editor, Feb.
