FORT WORTH — National Weather Service meteorologist Parker Davis pinched the neck of a big white balloon and extended it above their head.
“Counting it down,” Davis said. “Three, two, one. Off it goes.”
Twine tied to the balloon raced out of Davis’ hand as it floated up and away. The radiosonde on the end of the string followed into the sky.
Launching weather balloons to collect data from the atmosphere is a twice daily task at the weather service station in Fort Worth, typically done at 6 a.m. and 6 p.m.
“We’re sending them up at the same time that every other office in North America is,” Tom Bradshaw, the Fort Worth office’s meteorologist-in-charge, said. “In fact, every location around the world is sending them up at roughly the same time and the point of that is it enables the data you’re collecting to be synchronous and have some kind of unity to it.”
The radiosonde — a small box labeled “harmless weather instrument” with a GPS, temperature probe and barometer — collects second-by-second data on where the device is traveling and the weather conditions in the upper air like temperature, humidity, pressure and wind speed and direction.
“This is one of our primary ways that we find out what’s going on above the surface, which is where all the weather is,” Bradshaw said. “We have to know what’s happening 10, 15, 20, 30,000 feet above the atmosphere.”
Weather balloon launches haven’t radically changed since the weather service started utilizing them in the 1940s, Bradshaw said. He noted that it’s a relatively inexpensive tool that ascends at a controlled rate so the data collection is precise. Similar weather information is collected from equipment like satellites or commercial aircraft.
“We by and large still send these up because the accuracy of the sounding is unparalleled,” Bradshaw said.
The technology is largely automated nowadays, so as the hydrogen-filled latex balloon travels through the air data is instantaneously being sent back to the meteorologists’ computers. In real time, they track where the balloon is traveling and the temperature and dew point changing.
As the balloon rises, it will expand and eventually burst causing the radiosonde, attached to a parachute, to float to the ground. Flights can last upwards of two hours.
After a quality check of the data, it’s submitted to be used it worldwide analysis systems that create weather models and forecasts.
This reporting is part of the Future of North Texas, a community-funded journalism initiative supported by the Commit Partnership, Communities Foundation of Texas, The Dallas Foundation, the Dallas Mavericks, the Dallas Regional Chamber, Deedie Rose, Lisa and Charles Siegel, the McCune-Losinger Family Fund, The Meadows Foundation, the Perot Foundation, the United Way of Metropolitan Dallas and the University of Texas at Dallas. The News retains full editorial control of this coverage.