The National Warning System (NAWAS), a major component of the Civil Defense Warning System (CDWS), was established with the primary purpose of providing a capability to warn the nation of a threat of a nuclear attack. The Robert T. Stafford Disaster Relief and Emergency Assistance Act of 1974, Public Law (PL) 93-288, as amended by PL 100-707, authorized the President to utilize and make available the federal component of the CDWS, NAWAS, for the purpose of providing warning to government authorities and the civilian population in areas endangered by disasters. Under this act, NAWAS can be used for emergencies related to peacetime nuclear accidents, railroad disasters, downed aircraft, and warning of potential natural disasters (e.g. hurricanes, floods, tsunami's, and tornadoes). As part of an overall and effective warning method, NAWAS was envisioned as being suited for disseminating peacetime civil emergency warnings to state and local governments, who are responsible for further dissemination of warnings to other communities and the general public.
The National Warning System supports the nonmilitary actions taken by Federal agencies, by the private sector, and by individual citizens to meet essential human needs; to support the military effort; to ensure continuity of Federal authority at national and regional levels; and to ensure survival as a free and independent nation under all emergency conditions, including a national emergency caused by threatened or actual attack on the United States.
The National Warning System has major terminals at each State EOC and State Emergency Management Facility. Today, the system consists of what is effectively a 2200+ telephone party line. Obviously, it is more than a normal telephone system. The phone instruments are designed to provide protection for lightening strikes so they may be used during storms. The interconnecting lines are provided some protection and avoid local telephone switches. This ensures they are available even when the local system is down or overloaded.
The system is used by local officials thousands of times a year for emergency management coordination and response. One typical scenario is the use of the system during tornadoes. As storms are sighted, emergency managers in one town or county can communicate with their colleagues in other counties who are in the path of the storm, advising them as to direction, speed, and intensity. The drawback to this system is it relies on human intervention. If there is no one there to receive the communications the warning is not disseminated. This has resulted in missed tornado warnings. Today modernization and automation are planned in most telecommunications systems.
Both the National Warning Center (NWC) and the Alternate National Warning Center (ANWC) at Olney, MD, are staffed 24 hours per day and serve as the primary control for the National Warning System (NAWAS).