National Alert Warning System

Overview
Operated and maintained by FEMA, the National Alert Warning System (NAWAS) was originally created as part of the Civil Defense Act of 1950 in order to pass emergency information to the American public regarding an actual attack or an accidental missile launch against the United States. The NAWAS is available on a 24/7 basis as a non-secure, continuous, private line, telephone system and is used to convey warnings to Federal, State, and local governments, as well as the military and civil populations.

Although the original mission of NAWAS was to warn of an enemy attack or missile launch, the Robert T. Stafford Disaster Relief and Emergency Assistance Act of 1974 expanded the NAWAS mission to include warning for acts of terrorism, as well as natural and technological disasters and events. NAWAS is used by the National Oceanic and Atmospheric Administration (NOAA) to pass severe weather alerts as conditions develop as well and to pass critical sheltering information in the event these severe weather conditions materialize. There are currently approximately 2050 NAWAS drops (referred to as Warning points) across the United States.

Source

 * National Continuity Policy Implementation Plan, at 64.