An early warning is a major element of disaster risk reduction. Multi-hazard early warnings simultaneously address flooding, storms and other major hazards. Long before such hazards arise, early warning projects prepare those at risk as well as those who may be involved in providing assistance so that they will be weather-ready when warnings sound. Impact-based early warning provide more understandable information to those that need to act on the warnings.
To be effective, early warning systems need to actively involve the people and communities at risk. Impact-based, multi-hazard early warning systems incorporate communities, political leadership, weather forecasters, disseminators of warnings, media, emergency response authorities, health facilities and recovery plans. By ensuring strong coordination among all relevant stakeholders, they are more effective and cost-efficient than stand-alone, single-hazard systems.