An outdoor tornado siren provides warning of approaching danger. Initially designed to warn of air raids, outdoor siren systems have been adapted to warn of natural phenomena such as tornadoes. The limited effectiveness of the outdoor warning siren has led them to be included as part of a multi-faceted public warning system which also includes the NOAA All Hazards Weather Radio system and the Integrated Public Alert and Warning System (IPAWS).

The NOAA All Hazards Weather Radio system is a network of radio stations broadcasting continuous weather information directly from a nearby National Weather Service (NWS) office. NOAA Weather Radio broadcasts National Weather Service warnings, watches, forecasts and other all-hazard information 24 hours a day. It also broadcasts alerts of non-weather emergencies such as national security, natural, environmental, and public safety information such as Amber Alerts.

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.

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 (cell phone alerts), the National Oceanic and Atmospheric Administration (NOAA) Weather Radio, and other public alerting systems from a single interface.