some timely form of either written or verbal indication of an impending event; advance notification of a problem in time for appropriate possible actions.55,56

The provision of timely and effective information through intensified institutions that allow individuals exposed to a hazard to take action to avoid or reduce the risk and prepare for effective response. Early warning systems include three primary elements: forecasting of impending events; processing and dissemination of warnings to political authorities and population, and undertaking appropriate and timely action.

A warning of an imminent threat (dangerously bad weather, military attack, etc) in time to take appropriate precautions to minimize damage and injury. (See also This Was Only a Test.) [SMB

early detection of an enemy ballistic missile launch, usually by means of surveillance satellites and long-range radar.