A 'Presidential Alert' will be sent to all cell phones on Wednesday, October 3rd (originally scheduled for Thursday, September 20th) as a practice test to assess the readiness of the emergency system and improve the system after testing.

Can you opt out?  Nope.

FEMA (Federal Emergency Management Agency) will be sending the alert to as a text message as part of its Integrated Public Alert and Warning System (IPAWS).  It will be integrating two existing alert systems, the Emergency Alert System and the Wireless Emergency Alert Systems and will be utilizing radio and television in the alert as well.

This will be the first alert sent by a president despite the system being established during George W. Bush's presidency.  FEMA states the use of this particular alert is a way for the President to connect directly in case of emergency situtations:

The EAS is a national public warning system that provides the President with the communications capability to address the nation during a national emergency.

The alert will look like this:

“THIS IS A TEST of the National Emergency Alert System. This system was developed by broadcast and cable operators in voluntary cooperation with the Federal Emergency Management Agency, the Federal Communications Commission, and local authorities to keep you informed in the event of an emergency. If this had been an actual emergency an official message would have followed the tone alert you heard at the start of this message. A similar wireless emergency alert test message has been sent to all cell phones nationwide. Some cell phones will receive the message; others will not. No action is required.”

For more information, check out the communication piece published by FEMA on their website.