Forecasters face loss of weather balloon data

The National Weather Service has cut back on weather balloon launches at some of its sites because of shortages of hydrogen and helium used to lift them, potentially affecting forecasts and weather and climate research.

The cutbacks, coupled with the closing of a launch site on Cape Cod last year that has yet to reopen, could especially affect forecasting in the New York- New England area, some scientists said.

The agency said it would use data from balloons launched at nearby sites and from its other sources, including ground-based sensors, satellites and commercial airliners.

While balloons have certain advantages, including the ability to make observations up to a height of about 20 miles, “This temporary adjustment will not impact weather forecasts and warnings,” the agency said in announcing the cutbacks last week.

But Troy Kimmel, a meteorologist and lecturer at the University of Texas in Austin, said any reduction in observations was concerning.

“We can’t go back and get that data,” said Sandra Yuter, a professor at North Carolina State University and an expert on remote sensing of meteorological data. “We’re going to have big gaps.”

Yuter said the cutbacks showed that the weather service was not placing high enough priority on weather balloons, which have been a staple of the agency’s observations for nearly a century.

The gas shortages are a solvable problem, she said.

Susan Buchanan, a spokesperson for the National Weather Service, said, “We take this situation seriously and are pursuing all avenues to resolve it.”

“The upper air observing program remains a key contributor to our analyses, model data assimilation, and for our forecasters’ situational awareness,” she said.

Weather balloons, which are about 5 feet in diameter when launched, carry a small, expendable package of instruments called a radiosonde that transmits data on temperature, pressure and relative humidity as the balloon rises into the upper atmosphere.

The balloon eventually bursts and the radiosonde descends by parachute to the ground, where it can be recovered and reused.

Balloons are used around the world and are usually launched at specific times twice daily, 12 hours apart. The data is fed into computer models that provide shortand longer- term weather forecasts, and also becomes part of large long-term databases used in weather and climate research.

The weather service announced March 29 that, effective immediately, flights from nine of its 101 launch sites in the United States and the Caribbean would be reduced “due to a global supply chain disruption of helium and a temporary issue with the contract of one hydrogen supplier.”

The agency said it expected additional sites would be affected.

The helium market has been affected this year by problems at the main domestic source, in Amarillo, Texas, and by a fire in January at a major new plant in Russia.

The affected sites are all in the East, from Tallahassee, Fla., north to Buffalo and Albany in New York. Five use helium and four use hydrogen.

Flights would be reduced to one a day and eliminated completely on days with good weather, in order to conserve gas for launches during hazardous weather, the service said.

On Monday, Buchanan said helium had been delivered to one site, in Greensboro, N.C., and a full launch schedule had been resumed. But some of the other affected sites had or would soon completely run out of gas, she said.

The issue with the hydrogen supplier had been resolved, but it was unclear when deliveries of the gas would resume.

By measuring conditions through the air column, radiosondes provide information that is crucial to understanding and forecasting the evolution of storm systems. Even if the weather is calm, collecting that data could be important, Kimmel said.

“Who’s to say that that calm weather pattern is not going to affect what they forecast for other places?” he said.

While the weather service was facing a “tough situation,” Adam Sobel, an atmospheric scientist at Columbia University, said he did not think their statement that there would be no effect on forecasts was credible.