FEMA is committed to continuously improving the national alert and warning systems and supporting local authorities in getting effective and timely warning to people.
There will be a second alert at 7.20pm BST (2.20pm ET), which will instead allow the US President to communicate trough radio and television. But the concern over an emergency alert earlier this year in Hawaii is being used as an example of what can happen. Some people may get the alert a bit later depending on cell phone tower issues.
FEMA officials said Tuesday they would share test result data on how the testing went with mobile carriers to help ensure the system works well in a true emergency.
The alternative is to buy a phone which isn't WEA-compatible, but most newer wireless phones are.
"This is a test of the National Wireless Emergency Alert System". It was just a test, and the real thing would only be used during a national crisis when it would be necessary to immediately contact all citizens. The presidential alert is like those, only it goes to virtually every cellphone in the country, and you can't turn it off. The goal is to have phones get the alert at the same time.
A tone will sound, mirroring previous alerts you may have received, like Amber Alerts or flood watch warnings.
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Has an alert like this been sent out before?
Unlike the Amber and weather alerts, the presidential alert can't be turned off.
She said the warning for that specific tornado came via stormspotters reporting to the National Weather Service, who then saw that the appropriate tornado sirens went off in the area. If you get the message, that means everything is as it should be!
The alert will appear as long as the device is on, and may also show up on smartwatches, according to officials.