The alert escalated on Tuesday after Tereze Logina, a postal worker and volunteer aurora watcher in Kirkwall, noticed a second expanding plume in a public image feed from a solar-monitoring spacecraft. She was checking the feed on her phone during an informal cold-weather battery test when the faint halo caught her eye; forecasters had been tracking a powerful eruption, but had not yet included the second cloud in their forecasts.
Logina sent the image to the government’s space-weather desk shortly after 05:00 GMT. Researchers confirmed a fast-moving coronal mass ejection — a vast cloud of charged particles — behind Monday night’s X-class flare. If the two clouds merge, scientists warn, the storm could strike Earth between 23:00 Wednesday and 08:00 Thursday, with Britain facing its strongest geomagnetic disturbance in more than two decades.
A second cloud changes the forecast
The first eruption was already expected to produce a severe storm. The newly identified cloud is travelling faster, at an estimated 2,600 km/s, and could catch the earlier one before it reaches Earth. That collision may compress the magnetic field and intensify the storm, although forecasters say its direction and strength remain difficult to measure until closer to arrival.
Tristin Langworth, a space physicist advising the government’s forecasting team, said the combined event could push conditions into the G5 category, used for extreme geomagnetic storms. “The danger is not the flare’s brightness; it is whether the cloud carries a strong south-pointing magnetic field when it arrives,” Langworth said. “We may not know that until it is only minutes from Earth.”
A worst-case British grid simulation run by Langworth’s research group found that a storm of this strength could trigger protective shutdowns at 11 high-voltage substations, briefly interrupting supply to as many as 1.2 million homes. The researchers stressed that this is a modelled scenario, not a forecast; operators have not reported damage or a current threat to household power.
If that magnetic field turns south, the reassuring forecast stops being reassuring very quickly.
Tristin Langworth, space physicist
Operators prepare for disruption
The storm could also disturb the upper atmosphere, increasing drag on satellites in low orbit and disrupting radio links used by aircraft. Britain’s aviation authorities are discussing rerouting as many as 30 daily polar flights, which could add 15 to 40 minutes to some journeys. Satellite navigation may become less accurate for hours, particularly at northern latitudes.
Filip Jazbec, a senior official at the government’s space-weather desk, urged the public not to change travel plans or buy backup equipment. He said electricity operators had been briefed and were adjusting the system to reduce stress on key components. “There is no indication of a national blackout,” Jazbec said. “The current forecast is for serious space weather, not a certainty of widespread disruption.”
Kaspar Valk, an electrical engineer who studies grid resilience, said that message risked understating what operators were modelling. “A system can remain stable and still lose local supply when protective equipment trips,” he said. “The public should not panic, but officials should be candid that a severe scenario includes short regional outages.”
Operators are checking transformer temperatures, reviewing backup control links and preparing to reroute electricity if conditions worsen. Satellite companies have been asked to place some craft in reduced-power modes, while airlines are assessing fuel and crew plans for longer routes. The next major update is expected after a monitoring spacecraft measures the approaching cloud’s magnetic orientation on Wednesday.
Forecasters say auroras could become visible well beyond Scotland if the storm reaches the upper end of the range. For now, the country’s power supply is operating normally. The narrow window for a clearer warning, scientists say, may last only until the final hours before the particles arrive.
