If all the cell phones around you spring to life with an ear-piercing alert this afternoon, fear not. It's not a flash flood, tornado, Amber Alert, or another potentially catastrophic event. It's just a test of a "Presidential-level" Wireless Emergency Alert (WEA), which will be used to notify Americans in the event of national emergency.
At 2:18 p.m. ET on Oct. 3, the Federal Emergency Management Agency (FEMA) and the FCC will send a test alert to all cell phones in the US.
It will sound much like the severe weather or Amber alerts with which mobile users are familiar. The WEA will read: "Presidential Alert - THIS IS A TEST of the National Wireless Emergency Alert System. No action is needed."
All wireless carriers that participate in the WEA system will send the alert; there are approximately 100 WEA carriers in the US, including the four major providers.
Still, senior FEMA officials estimate that only about 75 percent of US cell phones will actually receive today's alert. The phone has to be on and within range of an active cell tower during the test, and the alert won't interrupt phone calls or appear on phones with an active data session in the background.
Cell towers will also only broadcast the alert for about 30 minutes, so if you're on the phone or out of range for a half hour after 2:18 p.m. ET, you might miss it.
If you're in range, though, you're getting the alert whether you like it or not. You can't opt out as you can for Amber Alerts and other emergency alerts in your mobile phone's settings. The idea is that these "Presidential" alerts will only be used in such extreme circumstances, like a coordinated terror or missile attack, that sending the message outweighs your desire not to receive an alert.
They are noteworthy, according to FEMA officials, because of their reach. Most wireless alerts, like missing children messages, are sent by local and state governments and confined to phones in a particular region. Weather alerts can be sent nationwide, but not all at once like Presidential alerts.
Today's alert is the first national test of the WEA system. Legislation passed by Congress in 2015 requires "nationwide testing of the system every three years," and this is test number one. Hopefully it will not traumatize those in Hawaii.
Officials will also conduct a test of the Emergency Alert System (EAS) on Wednesday, beginning at 2:20 p.m. ET, which goes out to radio and television stations, so don't freak out. This will be the fourth nationwide test of the EAS after similar tests in 2011, 2016, and 2017.
When news of these presidential alerts were first publicized, meanwhile, some characterized them as a way for President Trump to send out nationwide texts to everyone as simply as he might send a tweet. Rest assured that while these alerts originate at the White House, Trump himself does not press send and they are reserved for only the most dire of circumstances.