Weather balloon, top; parachute, middle, radiosonde instrument, bottom. (National Weather Service)

Weather balloons collect data that is essential for forecasts all around the world. But because of staff shortages, the National Weather Service has substantially cut back on launching these instruments at six locations in Alaska.

The Weather Service has suspended about 24 balloon launches per week, or 25 percent of the standard, according to Jim Brader, a representative of the National Weather Service Employees Organization, a labor union. This number is even higher when existing staff are out sick or on leave.

(Spreadsheet obtained by The Washington Post and adapted for explanatory purposes.)

Weather balloons collect temperature, pressure, wind and moisture information at different levels of the atmosphere. The data obtained are essential inputs to both U.S. and international computer models that provide global weather forecasts. In data-sparse regions such as Alaska, they can be particularly important.

“They are critical especially in areas where we don’t have other observations,” said Ryan Maue, meteorologist at Weather.US. “We shouldn’t get into the habit of skipping these. When you have a weather system in which the upper-level ingredients are coming together five to six days out, you don’t want to introduce even small forecast errors as those errors can grow over time — and lead to forecast degradation.”

During high-impact weather events affecting Alaska and other parts of the country, forecasters can request special balloon launches, but Brader said even many of these requests are being rejected due to lack of resources.

“We currently are challenged to make all the launches in some remote areas of Alaska,” said Susan Buchanan, Weather Service spokeswoman. “Missing these launches brings our radiosonde network availability to 98 percent nationwide, which is still above our operating standard” 96 percent.

Buchanan said the impact of the missing launches on model forecasts “is minimal.” She attributed the problem to a “slow hiring process” and challenges in “recruiting and retaining qualified personnel” for these posts.

“We currently have a large number of hiring actions in the queue for these locations and are considering hiring incentives to encourage people to apply for positions in the more remote areas,” she said.

Three people are supposed to staff each of six Alaska weather outposts and conduct launches twice daily. But 30 percent of the positions are vacant. “Some of the stations only have one or two people,” Brader said.

Brader said workers had become accustomed to working for a month without a break due to the staff shortages. He said one employee worked 145 days straight in McGrath, one of the six stations.

While staff went to great lengths to sustain the balloon launches and attend to other duties, Brader said the Weather Service decided to stop paying them overtime starting in late August. “It basically said people could work five days a week and that was it,” he said. Since then, the number of weather balloon launches has tanked.

Troy Kimmel, a meteorology instructor at the University of Texas-Austin, keeps tabs on daily weather balloon launches around the country. In recent weeks, he noticed “an inordinate number” of balloon releases missing in Alaska. He said he found it “amazing” that the Weather Service was neglecting the standard twice daily launches.

“As a meteorologist, I’m very concerned,” he said.

An administrative message from the National Weather Service showing the log of scrubbed or failed weather balloon launches Oct. 30. The three locations boxed in red are from the Alaska outposts Kotzebue (OTZ), Bethel (BET) and McGrath (MCG) and indicate “ascent not authorized.” (National Weather Service, adapted by CWG)

The Weather Service is working toward automating weather balloon launches, Buchanan said, and “a demonstration project is underway in Alaska.”

Dan Sobien, president of the union, said the reduced weather balloons launches are “just another example of degradation of weather services because of the staffing situation.”

Hundreds of positions remain vacant at the Weather Service throughout the country, and it is rolling back some services in the Lower 48 as well.

On Thursday, the Weather Service announced that it would no longer be issuing national discussions and graphics about heavy precipitation events, including flash floods, overnight between 8 p.m. and 5 a.m. Eastern, during routine weather. It said it will also no longer issue a more general overnight weather model discussion. In both cases, however, it said the products will be provided around the clock when the weather is severe.

The Weather Service employees union said the responsible national center for issuing these products, based in College Park, Md., has six unfilled positions and four additional staff about to go out on maternity and paternity leave.

Correction: This story originally said the six Alaska weather station are supposed to be staffed by four people; the correct number is three, and has been revised.