SURVIVE THE STORM: How weather balloons are key in forecasting

Besides satellite and radar meteorologists use a weather balloon to find out what’s happening the atmosphere. Here’s how it works.

"It’s one actually primary tools the national weather service uses in part of their forecasting," said Gene Hatch, National Weather Service Meteorologist. "The instrument package that balloon carries in the atmosphere sends back atmospheric data.”

Gene Hatch, meteorologist at the Springfield National Weather Service office says a latex balloon is tied to a radiosonde. “The instrument package with the temperature sensor and the humidity sensor are just on this little boom here,” Hatch said. The sensors record the temperature, humidity, pressure, wind direction and wind speed at every level of the air.

“Without this information we would gather from the radiosonde that we release every day we actually would have very limited information that we would be able to put in the to the weather models,” said Hatch. Balloon launches are done twice a day.

It's filled with 1500 grams of hydrogen. Then the radiosonde is attached. “This train that we do needs to be at least 100 feet long,” Hatch explains. The balloon will travel up in the atmosphere for about an hour and a half. As it rises it expands, reaching the size of a two story house before it pops at around 100,000 feet. Within seconds it’s up thousands of feet.

The data is relayed back to the upper air antenna. From there it’s decoded and downloaded. “Sometimes in less than 10 or 15 minutes that information will be processed,”said Hatch.

It’s displayed in a graph form that’s called a sounding on a weather chart. “The red line here. This is actually the temperature as this goes up in the atmosphere," Hatch shows. "You can actually see an inversion where the temps warm with height.”

It’s essential during rapidly changing conditions. Once the balloon pops a parachute guides it back to earth.

If you find a radiosonde there’s a prepaid package on the inside. Just mail it back to the national weather service and they’ll recycle it.