Warning system
system of biological or technical nature deployed by an individual or group to inform of a future danger
ground proximity warning system
AMBER Alert
Earthquake Early Warning
security alarm
Missile Approach Warning
collision avoidance system
Deep-ocean Assessment and Reporting of Tsunamis
NINA
tsunami warning system
Head on a spike
stick shaker
acoustic mirror
threat level
early warning system
Earthquake warning system
Emergency Alert System
National Severe Weather Warning Service
Silver Alert
Mid-Canada Line
warrant canary
fire alarm system