The primary tool to notify the public is an Outdoor Warning Siren System placed at various locations in the 10-mile Emergency Planning Zone (PDF). Upon activation, the sirens will sound for approximately 3 minutes with a steady, high-pitched sound.
Residents should turn on radios or televisions to receive Emergency Alert System (EAS) warning messages. County officials use the Emergency Alert System to provide emergency information and instructions.
KTAR 620 (AM) and 92.3 (FM)
KMVP 98.7 (FM)
Phoenix National Weather Service forecast office transmits via the National Oceanic and Atmospheric Administration (NOAA) Weather Radio South Mountain transmitter, KEC 94 (FM) on 162.55 MHz.
All radio and television stations serving the affected area(s) will be asked to broadcast emergency information as a public service.
Should a siren(s) fail the Maricopa County Sheriff's Office will provide warning by telephone, door to-door contact or loudspeakers mounted on patrol or other vehicles as necessary.