One unanswered question is when the legions of Apple iPhone users like Burns will be able to receive alerts.
Buchanan said iPhones are supposed to join the system in the fall, but she didn’t know if that means only new iPhones, or if software upgrades will make older models capable, too. Representatives of Apple Inc., which is highly secretive about its product upgrades, did not respond to several messages seeking details.
FEMA’s system carries three kinds of alerts: presidential alerts, which might deal with national security information such as terrorist attacks; imminent-threat alerts, which include weather warnings as well as public-safety messages from local authorities; and Amber Alerts issued by law enforcement agencies for kidnapped children.
Phone users can opt out of the imminent threat and Amber Alerts, usually just by changing their settings, but they can’t opt out of presidential alerts.
Twenty-eight state or local emergency management agencies in about a dozen states are authorized to send imminent-threat alerts. Eighty-three others are in the process of getting certified.
Agencies have different ideas for the system. Minnesota is considering using it for chemical spills or nuclear accidents. In southern Florida’s Miami-Dade County, it might convey hurricane evacuation information.
Curt Sommerhoff, Miami-Dade’s director of emergency management, said the alerts will permit authorities to distribute urgent information to people in danger “whether you’re a resident, employee or visitor.”
The system doesn’t use the satellite-based global positioning system to determine a phone’s location. Participating carriers just send an alert out from every cell tower in the affected county. Capable smartphones pick it up.
So if a user from Minneapolis travels to Kansas City, Mo., that person would get local warnings for Kansas City, not their home city. That feature sets the system apart from weather apps that deliver information based on users’ ZIP code but don’t automatically update their locations when users travel.
Dan Smith, a photographer from Reston, Va., who was in Minneapolis for a convention, said he was worried that the messages could became intrusive.
“It’s like email. It used to be you only got stuff you wanted. Now you get 20 junk messages for every good one,” Smith said.
But Carbin said that in a typical year most smartphone users will probably receive relatively few weather alerts.
“Even in those areas of the country where there’s a lot of severe weather, the frequency with which you would be alerted is pretty low,” Carbin said.
Associated Press Writer Patrick Condon contributed to this report.