Machine auto launches weather balloons twice daily from Hilo

  • Kelsey Walling/Tribune-Herald Steve Butler with the National Weather Service calls the airport control tower before releasing a weather balloon near the Hilo International Airport on Monday.

  • Kelsey Walling/Tribune-Herald A weather balloon is automatically released from a machine operated by the National Weather Service near the Hilo International Airport on Monday.

A new piece of equipment at the National Weather Service station in Hilo makes light work of high-altitude weather monitoring.

An automatic sounding station went online at the Hilo NWS station last week, which automates the process of preparing high-altitude weather balloons to monitor conditions in the upper atmosphere.


NWS electronics technician Steve Butler said the sounding station — called an “Autosonde” by manufacturer Vaisala — is one of only a handful operating in the country.

“It’s a pricey bit of equipment,” Butler said, explaining that it cost the NWS about $800,000. “But our equipment has been getting old and wearing out so we’re updating and automating our technology.”

Of the NWS’s 95 upper-air observation stations, only 20 are equipped with Autosondes, including Hilo. The station in Lihue also has the device, as do 10 stations throughout Alaska.

The Autosonde attaches instruments to, inflates, and releases weather balloons entirely autonomously, which Butler says will save the station manpower in the long run. The Hilo station releases weather balloons to measure air temperature, pressure, wind speed and more twice daily.


Butler said the machine needs to be reloaded every 12 days, but otherwise requires no human input.

The balloons are filled with hydrogen generated from an on-site fuel cell and rise up to 100,000 feet, whereupon they burst and the instruments fall to the earth below — usually the ocean.