A tsunami warning sent in error lit up phones across the East Coast, apparently triggered by a monthly test of the emergency service.

The National Weather Service was quick to call the alert a false alarm after AccuWeather sent the notice around 8:30 am to users of its popular weather app.

People who received the alert quickly flocked to Twitter, questioning the validity of the alert, which read: “Severe Weather Alert: Tsunami Warning in effect for Portland, ME until 9:28 AM EST. Source: U.S. National Weather Service.”

Margaret Curtis, a forecaster at the weather service in Gray, said similar false alerts were sent to users along the entire east and Gulf coasts.

A monthly test was scheduled for Tuesday morning, but any information posted by the service was under a test banner, she said.

“It says across the top, test, test, test, test,” she said.

“For some reason, everybody with that app saw this test message,” she said, still puzzled as to why AccuWeather sent a push alert, and noting that users who opened the message were informed that it was a test.

Early Tuesday afternoon, AccuWeather placed the blame for the false alarm on the weather service, claiming that the test language “passed along” by the weather service was “miscoded,” prompting the company’s computer system to send an incorrect alert.

“The responsibility is on the NWS to properly and consistently code the messages, for only they know if the message is correct or not,” the company wrote.

The weather service said it’s still investigating the matter.

The false alarm came about a month after an employee at the Hawaii Emergency Management Agency misunderstood a routine test and sent a false alert that an incoming ballistic missile was headed toward Hawaii, causing a panic. Tuesday’s fake tsunami appeared to spark less concern among AccuWeather users, most of whom seemed to quickly figure out it was a misfired test.

The Tsunami Warning Center in Palmer, Alaska circulates regularly scheduled monthly tests between regional weather service offices, Curtis said. The information is publicly available to private, third party weather apps, such as AccuWeather.

In the event of a real tsunami threat, the weather service would inform the public in a more widespread and dramatic way, by interrupting radio and television broadcasts, much like in the event of a tornado warning, Curtis said.

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Callie Ferguson

Callie Ferguson is an investigative reporter for the Bangor Daily News. She writes about criminal justice, police and housing.