http://www.fema.gov/integrated-public-alert-warning-system#
During an emergency, alert and warning officials need to provide the public with life-saving information quickly.
The Integrated Public Alert and Warning System (IPAWS) is a modernization and integration of the nation’s alert and warning infrastructure and will save time when time matters most, protecting life and property.
Federal, State, territorial, tribal, and local alerting authorities can use IPAWS and integrate local systems that use Common Alerting Protocol (CAP) standards with the IPAWS infrastructure.
IPAWS provides public safety officials with an effective way to alert and warn the public about serious emergencies using the Emergency Alert System (EAS), Wireless Emergency Alerts (WEA), the National Oceanic and Atmospheric Administration (NOAA) Weather Radio, and other public alerting systems from a single interface.
View a list of IPAWS Organizations with Public Alerting Authority Completed in each state.
https://www.fcc.gov/consumers/guides/wireless-emergency-alerts-wea
Wireless Emergency Alerts (WEA) | Federal Communications Commission
“In passing the WARN Act, Congress allowed participating carriers to offer subscribers the capability to block all WEAs except those issued by the President.”
Alerts from WEA cover only critical emergency situations. Consumers will receive only three types of alerts:
Alerts issued by the President
Alerts involving imminent threats to safety or life
Amber Alerts
Participating carriers may allow subscribers to block all but Presidential alerts.
What do consumers experience when they receive a WEA?
A WEA alert is accompanied by a unique attention signal and vibration.
“WEA enables government officials to target emergency alerts to specific geographic areas – lower Manhattan, for example – through cell towers that broadcast the emergency alerts for reception by WEA-enabled mobile devices.”