• Millions were left without power across Europe, primarily in Spain.
• Induced atmospheric vibrations, caused by rapid temperature or wind speed changes, can impact power lines anywhere, including the U.S.

Preliminary reports out of Europe about the massive blackout that left millions powerless say the cause may have been something called “induced atmospheric vibration,” a rare phenomenon where weather changes affect power lines.

The outage was centered in Spain on Monday, where the lack of power caused widespread chaos. Renfe, Spain’s national railway company, said on social media that the “entire national electricity grid was cut off” at 12:30 local time.Portuguese energy company REN suggested that “due to extreme temperature variations in the interior of Spain, there were anomalous oscillations in the very high voltage lines (400 KV), a phenomenon known as ‘induced atmospheric vibration,'” according to a BBC.com report.

Could a similar power outage happen in US?

Spain’s Prime Minister Pedro Sánchez said a “strong oscillation” was behind the outage but said no conclusions about the cause could be determined yet, Weather.com said.

AccuWeather meteorologist Dan DePodwin told USA TODAY that “induced atmospheric vibrations” are rare but can occur because of rapid changes in temperature or wind speed. “The atmosphere does something to induce vibrations in power lines, which can lead to outages,” he said.

DePodwin added that it can occur “anywhere there are transmission lines,” including here the U.S.

This is a developing story. It will be updated as new information comes in.