In the event of dangerous weather emergencies, cell phone users may be notified by the National Weather Service’s new Wireless Emergency Alert (WEA) system.

Messages are sent by the National Weather Service (NWS) to cellular phone companies, and then distributed to all compatible phones in the affected area.

Wireless carriers representing more than 97 percent of subscribers voluntarily agreed to develop and offer free, geographically targeted wireless emergency alerts. In addition, cell phone users will also receive Amber Alerts, which warn to be on the lookout for missing children, and Presidential Alerts, issued directly from the President.

Customers of participating wireless carriers with WEA-capable phones will not need to sign up to receive the alerts; they should automatically receive WEAs in the event of an emergency if they are located in (or travel to) the affected geographic area.

Alerts will be issued for life-threatening events such as tornadoes, flash floods, hurricanes, typhoons, tsunamis, dust storms, extreme winds, blizzards and ice storms.

These text alerts will be very brief—less than 90 characters—and are intended to prompt people to immediately seek additional information through other information channels, such as the City Website (alexandriava.gov), Internet, television, radio or NOAA Weather Radio.

WEAs use a unique ring tone and vibration to signal that an alert has arrived. The unique vibration distinguishes the alert from a regular text message. Alerts will automatically “pop up” on the mobile device screen, but will not preempt calls in progress.

The new weather messages are part of the broader Wireless Emergency Alerts initiative – a partnership between the wireless industry, the Federal Communications Commission (FCC) and the Federal Emergency Management Agency, or FEMA. NOAA’s National Weather Service is one of many agencies authorized to send emergency alerts to cell phones through this new system.

Individuals will be able to opt out of Imminent Threat or AMBER alerts, which will be sent automatically. Individuals will not be able to opt-out of Presidential alerts.

Most alerts will be sent by the National Weather Service (NWS). The chart below illustrates the messages that NWS will be sending out.

If your phone's packaging has a sticker that looks like the illustration below, it will receive the alerts. Some other phones need software upgrades to receive them. To confirm if your particular phone will receive this service, contact your carrier.