Emergency alerts on phones are messages sent directly to mobile phones by authorized government alerting authorities. These alerts are part of the Wireless Emergency Alerts (WEA) system, which is an essential part of Americas emergency preparedness. The WEA system has been used more than 84,000 times since its launch in 2012 to warn the public about dangerous weather, missing children, and other critical situations.

When an alert is issued by the appropriate authorities, cell towers in the affected areas will pick up this alert and transfer it to all phones connected to that cell tower. The alert message will appear on the phones home screen or through something similar to a text message, accompanied by a unique ringtone and vibration.

There are four types of alerts that can trigger a WEA: Presidential Alerts, Imminent Threat Alerts, AMBER Alerts, and Public Safety Messages. Presidential Alerts are a special class of alerts only sent during a national emergency, while Imminent Threat Alerts include natural or human-made disasters, extreme weather, active shooters, and other threatening emergencies that are current or emerging. AMBER Alerts are urgent bulletins issued in child-abduction cases, and Public Safety Messages contain information about a threat that may not be imminent or after an imminent threat has occurred.

It is important to note that participating carriers may allow subscribers to block all but National Alerts. Alerts received at the right time can help keep people safe during an emergency, and with WEA, alerts can be sent to mobile devices when people may be in harms way, without the need to download an app or subscribe to a service.