On a spring day in 1967, radar operators at three Air Force early-warning stations in Alaska, Greenland and the United Kingdom watched their screens fill with interference at the same moment. For a brief window, commanders suspected the Soviet Union was jamming the country’s ability to see an incoming missile attack, and bombers were readied to respond. The actual cause was the sun. Nearly six decades later, researchers have built a new model that puts a dollar figure on what a storm of that kind would do to the modern power grid, and the numbers are large enough to treat space weather as more than a historical curiosity.
The Storm That Looked Like an Attack
The incident unfolded on May 23, 1967, when a powerful solar flare disrupted radio and radar systems across the Northern Hemisphere. All three radar sites belonging to the Ballistic Missile Early Warning System, the network built to detect an incoming Soviet missile strike, appeared to go dark or jammed at nearly the same time, a pattern that looked deliberate rather than accidental to the officers monitoring it.
Air Force officials initially assumed the Soviet Union was responsible, since jamming all three stations simultaneously through any means other than a coordinated attack seemed unlikely. Nuclear-armed bombers were prepared for takeoff before Air Force space weather forecasters, who had only recently been folded into the chain of command, were able to convince decision-makers that a solar event, not an adversary, was the cause. A detailed account of the incident, including how narrowly the forecasters’ warning arrived before any order was given, is documented by Space.com.
A New Dollar Figure for Modern Storm Risk
Researchers have now built a framework to estimate what a storm of comparable or greater intensity would cost the United States today, a system far more dependent on continuously running electronics than it was in 1967. The model, described in coverage from Phys.org, combines physics, power-grid engineering and economics to estimate the hazard, the grid’s vulnerability, and the resulting socioeconomic damage across storms of varying severity.
For a storm severe enough to occur roughly once every 100 years, the model projects that about 3.5 million people and 91,000 businesses would lose power, with daily economic losses near $1.22 billion. A rarer 250-year storm would be more damaging still, potentially cutting power to as many as 5 million Americans and more than 135,000 businesses, with direct losses estimated near $980 million per day and total daily losses, including indirect economic effects, reaching roughly $1.81 billion.
Why the Grid Is More Exposed Than It Was in 1967
A severe geomagnetic storm threatens infrastructure that barely existed in its current form in 1967. Large-scale electrical grids, satellite networks, GPS systems and the transformers that step voltage up and down across long-distance transmission lines are all vulnerable to the induced currents a strong storm can generate, and the country now depends on all of them simultaneously in ways it did not six decades ago.
High-voltage transformers are a particular concern because many take months to replace if damaged, and few spares are kept in reserve given their size and cost. A regional blackout caused by ordinary weather can often be repaired in days; damage to transformer infrastructure from a geomagnetic storm could leave parts of the grid offline for a much longer stretch while replacement units are manufactured and shipped. Communications networks, financial systems and water treatment plants that depend on stable grid power would face knock-on disruptions of their own the longer an outage of that kind persisted.
Forecasting Has Improved, but Warning Time Is Still Short
Space weather forecasting has advanced considerably since 1967, when the discipline was young enough that its practitioners had only just been given a seat in military decision-making. Satellites positioned to watch the sun now give forecasters a window, typically measured in hours rather than days, between detecting a major eruption and the moment its effects reach Earth.
That warning window allows grid operators to take some protective steps, such as adjusting transformer loads or preparing to disconnect vulnerable equipment, but it is not enough time to harden infrastructure that was not already built to withstand a severe event. The new economic model is intended partly to help utilities and regulators decide how much hardening is worth doing in advance, based on how much a major storm would actually cost if it hit unprepared infrastructure. Unlike a hurricane or an earthquake, a severe geomagnetic storm can affect grid infrastructure across multiple states or even multiple countries at once, which is part of what makes advance economic modeling useful for coordinating a response rather than relying on the kind of mutual aid utilities normally lean on after a regional disaster.
A Threat That Never Really Went Away
The 1967 incident is remembered today mainly because it came close to triggering a military response rather than because of the physical damage the storm caused, which was comparatively minor by modern standards. Later storms, including a major 1989 event that knocked out the power grid serving Quebec for hours, demonstrated that the physical risk to infrastructure is real independent of any military misunderstanding.
The new modeling effort treats that risk as an ongoing planning problem rather than a historical footnote, translating the physics of a major solar storm into figures that utilities, insurers and emergency planners can use directly. Researchers behind the work have said the goal is to give decision-makers a concrete cost estimate to weigh against the price of grid-hardening measures, rather than leaving the risk as an abstract, low-probability event easy to deprioritize.
This article was produced with the assistance of AI and reviewed by Morning Overview editors prior to publication.
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