At the foot of sheer Rocky Mountain slabs, on a secure federal campus in Boulder, Colorado, a woman seated alone in a dark room watches banks of computer screens that show in dozens of ways what’s happening 150 million kilometers away on the surface of the sun.
The information gathered by senior space weather forecaster Briana Kay Muhlestein and others at the Space Weather Prediction Center (SWPC) will be packaged and published on a website maintained by this office of the National Oceanic and Atmospheric Administration (NOAA).
It’s information from a host of sources developed for public consumption but used mainly by institutions and industries around the world, including warfighters, power companies, satellite operators, airlines, farmers, and even the Chinese Communist Party (CCP) and Russia. One of those sources is SWPC’s military counterpart — the 2nd Weather Squadron, running its own 24/7 Space Weather Operations Center at Offutt Air Force Base, Nebraska. To Muhlestein, the bright yellow disk whose only motion seems to be crossing the sky during the day is actually a storming ball of fire that, with little warning, can hurl disruptive charged particles, electromagnetic radiation, magnetized plasma and other phenomena Earth’s way.
Taken together, these assaults are known as space weather. They’re comparable to the terrestrial weather that drives all human activity in that there’s some shared vocabulary – storms, streams, loops – and that many operators and managers in the field are drawn from meteorology. Plus, NOAA is the global leader in efforts to understand, forecast and mitigate the impact of both types of weather.
But for practical purposes, the similarities end there. For one thing, people have come to respect warnings about a potential 15-foot, hurricane-driven storm surge shaping up off the Gulf Coast of Florida. They can see it. They’re unlikely to pay much attention to the possible power-grid impact from a severe geomagnetic storm, known more for the brilliant aurora waves it can push toward the equator from high latitudes. And while terrestrial weather predictions have reached reliable levels through the years, relatively little is known about how the sun works and what violence it may bring.
“The lead time here is a lot less,” said Muhlestein, who previously worked as a terrestrial weather forecaster, as she keeps an eye on an SWPC monitor showing movement at the edge of a sunspot. It takes just eight minutes for the energy from a solar flare to reach Earth. Muhlestein routinely worked with eight data models in her role as a lead terrestrial weather forecaster in Portland, Oregon. There are no comparable models yet with space weather. Said NOAA Lt. Cmdr. Bryan Brasher, a project manager at the center: “It’s as if you had a single image of a trough developing outside Africa and you had to say where a hurricane was going to hit Florida.”
Still, opportunities are arising for advances in space weather knowledge. The field is gaining greater attention, in part because of a confluence of developments. A presidential order in 2016 and an act of Congress in 2020 acknowledged the threats from space weather and ordered the establishment of baselines and benchmarks. In between, during 2019, before the outbreak of COVID-19, the Federal Emergency Management Agency (FEMA) called space weather and pandemics two of the most serious threats facing the U.S. population.
Then in October 2024, NASA, SWPC and a special international panel declared a peak — known as solar max — in one space weather pattern that science has succeeded in identifying: the solar cycle, a period of roughly 11 years when the sun flips its north and south magnetic poles and transitions from relatively calm to stormy and back again. At the same time, during the current solar cycle, the world has seen a dramatic increase over the previous cycle in the number of satellite constellations launched into low Earth orbit (LEO), about 2,000 kilometers up.
Demand for forecasts
The satellite community was caught off guard by the approaching solar max. They know their spacecraft are susceptible to space weather, but they’ve learned that forecasts suggesting what it is and when it’s coming can’t predict how strong it will be. One example: Solar winds and geomagnetic storms can heat the troposphere region that roughly overlaps with LEO, increasing its density and slowing a satellite’s progress — like running against the wind, as SWPC says on its website. Known as drag, or neutral density, this phenomenon can force satellite operators to expend precious onboard fuel to maintain orbit, shortening the life of a satellite, and complicate the delicate work of tracking spacecraft to avoid collisions.
Another example: Charged particles from the sun can interfere with signals from the GPS fleet and other satellites that make up the Global Navigation Satellite System (GNSS) in medium Earth orbit, about 20,000 kilometers up. This can degrade the precision of the vital position, navigation and timing data the satellites provide to a host of devices on Earth.
Solar max, typically lasting one to over two years, and the growing proliferation of satellites increase demand for more and better forecasting from SWPC. The center is housed on a former foothills ranch that’s now a Department of Commerce campus, in a four-story building of piled, flat sandstone rocks resembling the architecture at nearby University of Colorado Boulder (CU). The university supplies about half of SWPC’s budgeted 80-member staff. Tzu-Wei Fang, SWPC science division chief and commercial space liaison, recalls the demand for information spiking in February 2022 when 38 of 49 Starlink internet satellites launched in a single payload from Kennedy Space Center in Florida fell from orbit.
A study headed by Fang confirmed that the culprit was drag. The incident drew attention from across the industry, and operators started reaching out to SWPC. Fang helped bring them together for a meeting at the center in October 2023. “I said, ‘Why don’t you guys all come in and we’ll try to educate everybody?” she told Apogee. “Now, it’s like every storm that hits, I’m with them. They’re sending me email messages. So, we are supporting a lot of the commercial sector.”
SWPC hopes this relationship develops into more of a two-way street. With 11,000 active satellites tracked by the U.S. Space Force — a job that’s shifting to a Department of Commerce installation adjacent to SWPC — the center seeks all the data it can ingest from those who operate these largely commercial spacecraft. NOAA, SWPC and the National Weather Service (NWS) are part of Commerce.
More data is on the way, some of it from the latest addition to NOAA’s fleet — the Space Weather Follow On-Lagrange 1 (SWFO-L1) satellite. Set for launch in late 2025, SWFO-L1 will carry a suite of instruments to measure solar wind, thermal plasma and the magnetic field, and detect the fireballs known as coronal mass ejections (CME). It will occupy a sweet spot in space called Lagrange 1 or L1, about 1.5 million kilometers from Earth in the direction of the sun. From this vantage point, without Earth getting in the way, it will monitor solar wind, thermal plasma and magnetic field, and detect CMEs heading toward Earth. Forecasters also look forward to the launch in 2031 of the Vigil satellite from the European Space Agency (ESA), which will occupy another Lagrange orbit – L5 – to monitor the sun from the side so observers can get an early look at what’s happening on the portion of the surface that’s about to rotate toward Earth.
Briana Kay Muhlestein monitors solar activity. APOGEE STAFF
Sources of data
SWPC relies heavily on spacecraft, some positioned in L1 and, in the case of NOAA’s newly deployed GOES-19 satellite, rotating with Earth’s equator at about 36,000 kilometers altitude. GOES-19 is the latest in the agency’s Geostationary Operational Environmental Satellite series. L1 satellites like NOAA’s Deep Space Climate Observatory, or DSCOVR, can typically provide advanced notice of 15 minutes to 60 minutes before a CME reaches Earth. SWPC can provide warnings about certain solar phenomenon as much as one to four days out. Compare that to the drumbeat of warnings that can start more than a week before a terrestrial storm.
Other L1 satellites that SWPC relies upon serve mainly research purposes, so a forecaster facing deadlines must get in line for access to their data. During a severe geomagnetic storm in May 2024, rated G4 on a scale from G1 to G5 and the first such warning in nearly 20 years, the delay in receiving relevant data from NASA’s Solar and Heliospheric Observatory (SOHO) stretched for hours. “I just lost a third of my lead time because it was deprioritized for another purpose,” said Clinton Wallace, the SWPC director.
What’s more, satellites such as DSCOVR, NASA’s Advanced Composition Explorer (ACE) and SOHO are “long past their expiration date and designed life-span,” NOAA says on its website. SOHO is likely to run out of fuel within two years. Adding to the forecasters’ challenge is that the Joint Science Operations Center that NOAA helps fund — processing data from six solar telescopes positioned around the globe that provide high-resolution images of solar surface activity — was offline at the start of 2025 because a water pipe burst in a control center at Stanford University. SWPC forecaster Muhlestein showed a visitor how she now relies on backup images that resemble black-and-white Polaroids.
Delays or not, said Bill Murtagh, then SWPC program coordinator, forecasters don’t begrudge the resources put toward research because so much remains unknown about space weather. This includes the north-south direction of the magnetic field orientation between Earth and sun, known as Bz. “We don’t understand how to predict Bz, this most important thing,” Wallace told Apogee. “And we don’t understand what causes solar flares and when they’re going to flare, or even how the solar cycle works.” The entire space weather community eagerly awaits the latest revelations from research missions, including NASA’s Parker Solar Probe, which passed closer to the sun than any spacecraft in history in December 2024.
Space weather and the military
One partner who doesn’t make SWPC forecasters wait is the forecast group at Offutt AFB. The 2nd Weather Squadron serves specific Department of Defense customers, said Maj. Ross Malugani, Air Force liaison in Boulder to SWPC, but unclassified exchanges with SWPC are a matter of daily routine. The squadron relies heavily on SWPC’s satellite data and modeling, and SWPC sharpens its view of flare and sunspot activity through the Air Force Solar Electro-Optical Network with its telescopes in Australia, Italy, Hawaii and New Mexico. “There has to be a lot of interconnection at all levels to ensure that we’re progressing in the same manner,” Malugani said.
At the highest level of this collaboration is SWORM, the Space Weather Operations, Research and Mitigation Subcommittee, part of a Cabinet-level presidential advisory group that coordinates efforts among nearly 30 federal agencies and the science and research community. SWORM works to carry out the National Space Weather Strategy and Action Plan.
Militaries in the U.S. and worldwide follow space weather closely. They have much at risk. They fly their own satellites and use information from satellites flown by intelligence agencies and commercial operators. GPS applications are integrated into virtually every facet of U.S. military operations, according to GPS.gov, and nearly all new military assets — including vehicles and munitions — come equipped with GPS. In addition, solar flares can silence the high-frequency radio communication often used in long-range command and control for aircraft, ships, rocket launchers and other assets.
“The astronomical unit between here and the surface of the sun is wrought with gaps and challenges,” Malugani told Apogee. “But that is one of the things that SWPC, the Air Force and Space Force are all working toward over the next decade — to try to instill the right directives now so that as the technology advances and funding is available, we’re able to monitor and predict to the best of our ability how it can impact lives and missions.”
The growing commercial satellite community quickly came to understand the limitations in SWPC’s capabilities. “It’s from a lack of data. Satellite industry partners are shocked to learn how uncertain is the value we are looking at,” science division chief Fang said. “They complained to me about solar cycle predictions, and they said, ‘Oh, this is bad because we all planned on this revenue. Now we have to launch more, use fuel, maybe carry a bigger satellite so we can last longer.’ … They thought their satellites would last five years, but everybody fell off in three years.”
There has to be a lot of interconnection at all levels to ensure that we’re progressing in the same manner.” ~ Maj. Ross Malugani. Air Force liaison in Boulder to SWPC
The three-day exercise with satellite operators in October 2023 fostered a frank back-and-forth among SWPC, government offices such as FEMA and the Air Force Research Lab, international partners like the University of Manchester in England, and some of the biggest names in commercial space: Starlink operator SpaceX, Amazon’s Kuiper, Planet, LeoLabs, Slingshot and Sierra Space, among them. Fang, who conducted many of the sessions, compared this relationship with SWPC’s support for power companies that have long relied on the agency for warnings about the solar phenomena that can disrupt their systems. “I think with the satellite industry, we’re at the very beginning stages,” she said. “We’re making progress.”
The exchange was billed as a “testbed” but functioned more as a series of tabletop exercises that helped reveal the need for the real thing — a dedicated, purpose-built collaboration tool similar to testbeds run by the NWS and other federal agencies. Now, a state-of-the-art center to house a new testbed is nearing completion at the Boulder offices, one designed eventually to mirror the SWPC forecasting center downstairs.
Making a testbed
The potential impact of solar radiation on astronauts during the Artemis lunar mission was scheduled as the first Space Weather Prediction Testbed session, in early 2025 — about a year before the mission’s scheduled launch. SWPC, working with NASA’S Space Radiation Analysis Group, will host the two-week gathering. Other participants will include the University of Malaga in Spain, which has developed an upper atmosphere radiation model. One goal of the testbed process is to gather the broad cross-section of people who work on space weather and more effectively convert and refine research in the field into tools that forecasters can put to work. It’s a process called R2O2R, research to operations to research.
“Customers, partners, private industry as well, and also our research community, will come in and really get that operations-to-research experience,” Chris Siewert, then SWPC testbed coordinator, told Apogee. “We have them sit down with the forecasters while the forecasters are trying to make a forecast and explain the needs they have and really get that feedback fully. That’s something that has been lacking in the space weather community for some time. Research has been saying, ‘You need to show me what you want.’ It’s much easier just to show up and participate through some of these exercises that we’re going to run.”
Added SWPC director Wallace, who pushed to establish a testbed when he took over SWPC six years ago, “You put that forecaster with a researcher, an end user, a software developer, a policymaker, etc., etc., put them all physically around the same table, I promise you’ll get more work done in one week examining that problem than people going back and forth over email and conferences where you stand and deliver. It’s incredibly effective.”
Key to improving forecasting is commercial data, Wallace said. Space weather lacks the separate research component and funding that flows to terrestrial weather research, he said, so federal agencies and industry working together must fill the gaps. “Any flying vehicles, we could instrument them instead of flying our own satellites. Share their data. We’re in discussions about how to make it happen.”
With data from commercial space, researchers could better understand the space weather forces at work on objects in orbit, Fang said. “The first time I talked to Starlink, they said, ‘Why don’t you put 100 spacecraft around the sun, it would solve the problem.’ With our way of planning and budgeting, we’re not going to get there, even with four or five. How can we get the commercial sector to lead that more challenging, risky approach?” She added, “We need so much data from them and they’re almost scared of sharing.”
Reluctance to turn over data may arise from concerns that it’s proprietary or that it reflects operator mistakes, said Rob Steenburgh, science and operations officer at SWPC. “Depending on the sector that’s affected, there’s varying degrees of willingness to share, and say, ‘Oh yeah, this hurt us.’” A great deal is at stake with the buildup of satellites in low Earth orbit, Steenburgh told Apogee. “They’re flying a tight formation. There’s a lot up there and a bad storm with not enough warning or an inability to interact with the vehicles in a way to keep them safe could be catastrophic.”
Space weather kingpins
Feedback from the satellite community is changing how SWPC designs some of its products, said Shawn Dahl, service coordinator. For example, the center now provides solar cycle progression reports every month — more often than it did before. SWPC also is responding to demands to share more of its data, even if it doesn’t meet earlier standards of reliability. “We’re working on the balance between confidence and timing in warnings,” Dahl told Apogee, “to see if the satellite community is more tolerant of false alarms.”
Beginning with its 2022 Starlink satellite loss, SpaceX has worked with SWPC to provide data that’s helping improve forecasting models, Wallace said. Their joint response was swift, “to better characterize low- and very-low Earth orbit environments, and satellite system updates,” CU Boulder said in a news release at the time. Wallace also seeks to allay concerns about proprietary information, noting that the NWS has a long history of protecting trade secrets shared with the service.
The Starlink incident highlighted SWPC’s success at making its research actionable. Years earlier, with funding from the Department of Defense and the National Science Foundation, Fang led an effort to improve understanding of the ionosphere, which in turn helped mitigate its impacts on GNSS signals and satellite operations. Charged particles in the ionosphere, Earth’s upper atmosphere, cause signals to bend and slow down. The model resulting from Fang’s research was operationalized for end users. “In subsequent years, 2022, when satellites started falling from the sky, people were saying, ‘Oh, we need a neutral density product.’ And then I say, ‘Yeah, our model has neutral density; we just never released it and obviously didn’t have time to evaluate it in the way it needed.’”
Within a year, her team accomplished that, too, and helped end users understand how to apply the data in understanding drag. This project, called WAM-IPE for Whole Atmosphere Model-Ionosphere Plasmasphere Electrodynamics, also highlights the never-ending nature of research as R2O2R: “Now, they’re asking, ‘How do we upload that data to our spacecraft?’”
One of the strengths of SWPC is having researchers embedded with forecasters, said Steenburgh, whose job straddles both disciplines. The testbed may help advance this. “We’ve been trailblazers in that respect in the forecast office, where we’ve been able to bring things in quickly, and even if they weren’t fully formed yet, extract some value from them. The other side of the sword is you’re so nimble that things fall by the wayside and people think they’re done. And so, we get something that is halfway there and is already giving us good stuff to work with, but there’s so much more potential.”
Anyone, anywhere in the world, who has an interest in space weather relies upon the pioneering work of SWPC. “There’s nobody as robust and as resourced as us,” Murtagh, program coordinator on SWPC history and strategic alignment, told Apogee. “We’re the kingpins and it’s largely because of the multibillion space satellite support that we have within NOAA, our own satellites. No one else does that. … They all rely in large part on observations from the United States.”
A chart developed to rank threats, called the NOAA Space Weather Scales and modeled on the NWS Saffir-Simpson hurricane scale, has been adopted worldwide. Scales, undergoing independent review and a possible update, resides at the SWPC website, where the Products and Data tab provides a comprehensive picture of all that’s known to be happening on the sun. Even China and Russia use the U.S. data when they take their two-week turns among four groups of nations at the helm of the International Civil Aviation Organization space weather monitoring program.
International cooperation
SWPC has helped a number of nations establish space weather centers, and today, the network known as the International Space Environment Service has 22 members — from Argentina to the United Kingdom. They share information on an operational level, even with China. One example is what turned out to be a G4 alert in the final days of December 2024. Australia and the U.K. didn’t think a geomagnetic storm would develop, so they suggested issuing no notification, Dahl recalled. “We did, and we were right. That’s why we all collaborate.” The German space agency, known as DLR — for Deutsches Zentrum für Luft- und Raumfahrt — called into SWPC in January 2025 to discuss future collaboration.
SWPC has benefited from these international relationships, Steenburgh said — in technical progress, policy development, interacting with customers and developing products. “The absolutely amazing and wonderful thing is because these guys are starting fresh, they don’t have any legacy baggage. … That fresh start allows them to bring new ideas and revolutionary techniques into operations quickly because they take what works, they leave behind what doesn’t, and they charge ahead.”
So far, space weather warnings and the response by operators have helped forestall the most serious of impacts, Wallace said. That’s one reason most people don’t worry or even know much about it. Said Steenburgh, “A regular person walking around on Earth from day to day; unless you see the aurora, you’re never going to know about space weather. I was a meteorologist for years, I was in the military, and I didn’t know about space weather.” Few would have experienced the impact from the G4 storm that SWPC warned of in May 2024, or from the two more G4 storms that occurred before the year was out. But many did, including those who rely on precision GNSS signals to pinpoint location within a centimeter or two.
Wallace learned this firsthand during a visit with relatives who farm in the Dakotas that overlapped with the four-day geomagnetic storm in May. “They were telling me all kinds of crazy stories about how their planting machines would come to the end of the row and stop, or veer off into the neighboring field,” he said. Some 70% of planting operations rely on precision GPS to guide them along predetermined paths, he said, and farm damage estimates from the May storm approached $500 million in the U.S. alone. A GPS error of a few meters has little effect on a car driving on the road, but can hobble ocean drilling, bridge building, aviation and other precision work. Civilian and military aviation have backup systems when GPS fails.
With its customer base expanding, SWPC faces communications challenges that rival its data challenges, Dahl said. A top priority of the center has always been informing operators of the North American power grid about space weather threats from geomagnetic storms, which can cause widespread problems with voltage control and protective systems, and even blackouts — largely in the northern latitudes where space weather effects can be most severe.
The entire power grid in the Canadian province of Quebec shut down in March 1989 when a large impulse from a geomagnetic storm erupted along the Canada-U.S. border. Just 92 seconds later, a chain reaction in the system brought down the Quebec grid. Some 200 lesser but significant anomalies also were recorded across the continent, chiefly in New England, the Mid-Atlantic and the Midwest regions of the U.S., according to a report published by the U.S. Federal Energy Regulatory Commission. Years of collaboration and laws mandating timely communication have streamlined notifications to power systems. So have relations with a central contact for SWPC — the North American Electric Reliability Corp. (NERC), a nonprofit that regulates reliability and security.
A broader audience
There is no NERC in the satellite community, or among the much larger community that depends on vulnerable GPS signals. These include emergency services, construction, mining, surveying, package delivery, supply chain management, communications networks, banking systems and financial markets. New communication strategies are called for, Dahl said, and SWPC efforts are expanding through tools like social media, the messaging app Slack and dedicated channels modeled on NWS initiatives.
“We were a technical organization built for engineers and scientists, initially,” Steenburgh said. “I didn’t have to tell the scientist what the ionosphere was. If he was operating in this building, he knew. As we expanded our reach and as the interest in space weather has grown, I’m talking to people who don’t speak space. When I go to D.C. and talk to policymakers, they don’t want to hear about proton flux.”
Forecasters also consult daily by phone about real-time conditions with customers and partners, including satellite operators, NASA and Air Force counterparts. Murtagh got a lesson in the broad range of people who make use of the information SWPC churns out when he answered the phone during the years he worked as a forecaster on the operations center floor.
One call came from a criminal defendant who wondered if space weather would get him in trouble by throwing off the accuracy of his GPS-enabled ankle monitor. A worried mother who couldn’t believe her son had been caught speeding called to ask whether solar flares could compromise a police radar gun. And then there were the pigeon racers. Many of the birds are fitted with GPS monitors for tracking, but there’s a low-tech component, as well – and big investments at stake.
“Even moderate magnetic storms can affect pigeons’ ability to navigate,” Murtagh said, noting that many migratory creatures rely on the magnetic poles to find their way home. “Any time there’s a pigeon race scheduled, folks will look at the space weather website to see what the projection is for geomagnetic storming. You don’t want to mess with that; you’ll see online that at some of the big pigeon auctions, they will sell for in excess of $2 million a bird.”