Ken Graham had a plan.

When he became the director of the National Weather Service during the Biden administration, Mr. Graham introduced “Ken’s 10,” a list of priorities he hoped would streamline the department.

In January, addressing a conference hall full of meteorologists in New Orleans, he ticked off some successes, like replacing an antiquated and siloed communications system.

There were challenges, too: Outdated technology and a stagnant budget made it difficult to get employees to stick around. But in a speech that sounded almost like a sales pitch, Mr. Graham reminded those in the audience that their work saved lives and, at the cost to every taxpayer of about $4 a year, offered a great return on investment.

The crowd was skeptical. But Mr. Graham assured them the weather office fit into the incoming administration’s agenda. The agency was already lean and had a plan to be more efficient. He just needed time.

Instead, a few weeks later, the Department of Government Efficiency, the initiative led by Elon Musk reshaping the federal bureaucracy, delivered the same order to the Weather Service that it has across the rest of the government: Make cuts. A lot of them.

Through layoffs and retirements, the Weather Service has lost nearly 600 people from a work force that until recently was as strong as 4,000.

The reductions cut across two vital functions of the agency: the work of collecting the data used to make forecasts, and the people who turn that data into crucial warnings when extreme weather is on the way.

Weeks ago, as people began leaving the agency, some offices curtailed the regular weather balloon launches that send back data to feed forecast models. In Oakland, Calif., an office that covers many of the state’s major airports had to rely on colleagues as far away as Los Angeles and Seattle, themselves stretched thin, to cover scheduling gaps.

Now the cuts have led to a staffing crisis so dire that at least eight of the department’s 122 offices will soon no longer have forecasters working overnight, said Tom Fahy, the legislative director for the union that represents Weather Service employees.

“It’s not a chain saw,” said John Sokich, a former director of congressional affairs for the Weather Service. “They’re using a hand grenade.”

Many fear the cuts already sabotaged one of the most competitive forecasting agencies in the world. But Mr. Sokich and others familiar with the Weather Service’s outdated structure wonder if the upheaval — chaotic and fraught as it is — might be the shake-up the Weather Service needs to bring about necessary changes to reorganize for a modern generation of forecasting.

Capitol Hill has shaped the Weather Service’s mandate for decades.

Congress has long tussled over how, and whether, to protect the idea of government forecasts.

Years before Apple put a forecast in everyone’s pocket, the Weather Service worked in the shadow of companies like the Weather Channel and AccuWeather, which turned government data into commercial forecast products. Those companies got so good at capitalizing on the Weather Service’s work that in 1995 one congressman was quoted saying he didn’t need the Weather Service, because “I get my weather from the Weather Channel.”

In 1992, the Weather Service Modernization Act created the current framework for the department and gave it one mission: modernize. Back then, the Weather Service was using radar technology developed in the 1950s and a layout of offices it inherited from World War II, and it soon had a network of higher resolution radars and more than 100 forecasting offices throughout the country. With better data and better ways to analyze that data, forecasts grew more accurate. Warnings came earlier.

Now that infrastructure is showing its age. Mr. Graham has warned it could see catastrophic failures by the 2030s, and some of his allies in Congress had been agitating to help replace it.

“Next-generation weather radar is going to be a quantum leap forward from what we have,” said Representative Frank Lucas, Republican of Oklahoma, adding that if his colleagues understood how much more advanced the technology could be, implementing it “probably would have already been done.”

Representative Lucas sponsored the other major piece of legislation that shaped the Weather Service recently. The Weather Research and Forecasting Innovation Act of 2017, signed by President Trump during his first term, allows the department to buy data from commercial providers and to use private companies to help launch its satellites.

Start-ups flourished in the wake of the law’s enactment, some using their own forecast modeling to create products, but all of them use Weather Service data.

Many of the newer weather companies have begun launching their own satellites to acquire data that they can then sell to the Weather Service, and using artificial intelligence in an effort to create better forecasting models. Some experiments have shown artificial intelligence is becoming better at forecasting some weather events.

Most recently Project 2025, the blueprint from the Heritage Foundation to which many of this year’s cuts across the government can be traced, proposed that the Weather Service “fully commercialize” its forecasting. Its critics, Representative Lucas among them, worry that taking the government out of the forecasting business could lead to public safety becoming subscription-only. “Is it going to be that the people with the most money can afford the best forecast?” he said. “I don’t know that it serves society or the economy.”

The Weather Service has long been understaffed.

Back in New Orleans, Mr. Graham ended his talk in January by looking across the crowd and saying: “It’s burnout. I feel it, too.” He added, “We’ve got to do something different.”

The Weather Service asks employees to work undesirable shifts in remote locations, using technology that isn’t as up to date as what they used in school or even on their phones, and it often pays less than the private companies. Many young graduates chose the companies instead.

But those who stuck around have often been drawn to its public service mission. The Weather Service’s forecasters study all that data they have collected and tell people when a tornado is racing near, how bad the hurricane season could be, where a wildfire might explode and how the wind can fuel it. Mr. Fahy said one of the offices that is unable to staff an overnight forecaster is in Jackson, Ky., in an area that has endured years of destructive flooding. In the first half of February, the office’s forecasters issued 22 flash flood warnings for many of the 33 counties it oversees, as heavy rain swallowed parts of the region. At least 11 people died.

The other offices, he said, are spread across Kansas, Central California, Wyoming, Michigan’s Upper Peninsula and Alaska.

Kim Doster, the communications director at the National Oceanic and Atmospheric Administration, the Weather Service’s parent agency, acknowledged on Wednesday that several local offices “are temporarily operating below around-the-clock staffing.” She said the department “does not anticipate a significant impact in services as we work to mitigate potential impacts and direct other regional offices to provide additional support.”

Those warnings are increasingly crucial as weather changes because of climate change. The science suggests that the United States can expect more unusual and severe storms as the world heats up. In the 1980s, the country experienced, on average, one (inflation-adjusted) billion-dollar disaster every four months. Now, there is one every three weeks, on average. (Last week, the government said it would no longer track how many such disasters there are.)

With the Atlantic hurricane season bearing down, the Weather Service’s supporters have been scrambling to blunt the effects of the recent cuts and make the case to the Trump administration that it was going too far. Five of the department’s former directors recently wrote an open letter saying they feared the cuts had been so deep that lives would soon be endangered. This week, The Washington Post reported the department was racing to fill 155 positions in the next two weeks.

“I don’t want there to be a case example of us missing a tornado because of fatigue,” said Representative Eric Sorensen, a Democrat who is also the only meteorologist in Congress.

In April, two large storms carved a path of destruction across Nebraska, producing multiple tornadoes. A week later, Representative Mike Flood, a Republican, stood outside the forecasting office in Omaha and announced that the state’s congressional delegation had convinced the White House to restore some of the staffing it had lost. A few days later, the office resumed some of its balloon launches.

A new agreement reorganizes staff.

Amid the scramble to find staff for the offices hardest hit by layoffs and retirements, the Weather Service and its employees’ union recently reached an agreement that lets meteorologists focus on “highest-value work.”

Forecasters’ basic tasks are the same on nice days as they are during blizzards: to tailor a forecast for their region. The agreement gives forecasters the flexibility to use a computer model as a starting point, or even the only point, on sunny days; it lets the model do the busy work, which, in theory, allows forecasters to focus on the most extreme weather.

“It’s the extreme events where the models don’t do as well,” Mr. Sokich said. “And the forecaster does better.”

Brian LaMarre spent a decade as the meteorologist in charge of the forecast office in Tampa, Fla., before taking a job last year that had him planning the next modernization phase of the Weather Service. “Not every office needs to do the day-to-day forecasting,” Mr. LaMarre said. “It gets pretty redundant.”

The haphazard layoffs have forced the department to accelerate what he called a mutual-aid concept, where offices can trade tasks based on which has better staffing. He described an agency in “survival mode” now, trying to implement what was meant to be a multiyear plan almost overnight.

But Mr. LaMarre isn’t around to implement it; he’s one of the hundreds who left this spring.